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12,871 results for “aging;”
Corneal endothelial morphology of healthy myopic Malaysian children of Chinese ethnicity aged 8-9 years and its association with axial length
<p>Clinical Relevance: This study is to further understand the effects of axial length elongation on the corneal endothelial cell's morphology in myopic children. Abnormal changes in the morphology of cornea endothelium are indicators of corneal stress or instability which could be linked to myopia. </p> <p>Background: To examine the morphology of corneal endothelium cells in healthy Chinese Malaysian school children with emmetropia and mild to moderate myopia and its association with axial length. </p> <p>Methodology: A total of 111 school children comprising of 37 emmetropes, 37 mild myopes and 37 moderate myopes aged 8-9 years old were recruited. Visual Acuity was measured using the LogMar chart, cycloplegic refraction was determined using an open-field autorefractor (Grand Seiko WAM-5100, Hiroshima, Japan) and refined using subjective refraction. Morphology of cornea endothelial cells [ECD- endothelial cells density, COV- coefficient of variation, HEX- Hexagonility and CCT-central corneal thickness] was evaluated using a non-contact specular miscroscope (Topcon SP-2000P). Axial length was measured with A-Scan ultrasound biometry (PacScan Plus, Sonomed Escalon, NY). The correlation between morphology of cornea endothelial cells and axial length were assessed using Pearson Correlation and Linear Regression Analysis. </p> <p>Results: There was no significant difference in cornea endothelial cells and axial length between gender (p>0.05). Significant reduction in ECD and HEX and increased COV was found in eyes of higher myopic power which had longer AL when compared to emmetropes (p<0.001). Except for CCT, all corneal endothelial cells parameters correlated significantly with axial length (p<0.05). For every 1mm increase in axial length, endothelial cells density decreased by 73.27 cells/mm<sup>2</sup>, hexagonality decreased by 2.32% and coefficient of variation increased by 1.75%. </p> <p>Conclusion: There were significant changes in morphology of cornea endothelial cells in young moderate myopic children of Chinese ethnicity at 8-9 years of age. This result provides normative data for Malaysian children of Chinese ethnicity that can be used for comparison and reference for clinical procedures, thereby facilitating decision making with respect to interventions for myopia control, especially in prescribing contact lens for children. </p>
Impacts of using different standard populations in calculating age-standardized death rates when age-specific death rates in the populations being compared do not have a consistent relationship: A cross-sectional population-based observational study on US state HIV death rates
<p><strong>Objective</strong>: To examine if the rankings of state HIV age-standardized death rates (ASDRs) changed if different standard population (SP) was used.</p> <p><strong>Design</strong>:<strong> </strong>A cross-sectional population-based observational study. Setting 36 states in the United States.</p> <p><strong>Participants</strong>: People died from 2015 to 2019.</p> <p><strong>Main outcome measures</strong>: State HIV ASDR using 4 SPs, namely WHO2000, US2000, US2mor020, and Eur2011–2030.</p> <p><strong>Results</strong>: The rankings of 19 states did not change when ASDRs were calculated using US2000 and US2020. Of the 17 states whose rankings changed, the rankings of 9 states calculated using US2000 were higher than those calculated using US2020; in 8 states, the rankings were lower. The states with the greatest changes in rankings between US2000 and US2020 were Kentucky (12th and 9th, respectively) and Massachusetts (8th and 11th, respectively).</p> <p><strong>Conclusions</strong>: State ASDRs calculated using the current official SP (US2000) weigh middle-age HIV death rates more heavily than older-age HIV death rates, resulting in lower ASDRs among states with higher older-age HIV death rates.</p>
Separating the effects of paternal age and mating history: evidence for sex-specific paternal effect in eastern mosquitofish
<p>Paternal age and past mating effort by males are often confounded, which can affect our understanding of a father's age effects. To our knowledge, only a few studies have standardized mating history when testing for effects of paternal age, and none has simultaneously disentangled how paternal age and mating history might jointly influence offspring traits. Here, we experimentally manipulated male mating history to tease apart its effects from those of paternal age on female fertility and offspring traits in the eastern mosquitofish (<em>Gambusia holbrooki</em>). Male age did not affect female fertility. However, males with greater past mating effort produced significantly larger broods. Paternal age and mating history interacted to affect sons' body size: sons sired by old-virgin males were larger than those sired by old-mated males, but this was not the case for younger fathers. Intriguingly, however, sons sired by old-virgin males tended to produce fewer sperms than those sired by old-mated males, indicating a potential trade-off in beneficial paternal effects. Finally, neither paternal age nor mating history affected daughter's fitness. Our results highlight that variation in offspring traits attributed to paternal age effect could partly arise due to a father's mating history, and not simply to his chronological age.</p>
Measurement report: On the contribution of long-distance transport to the secondary aerosol formation and aging
<p>(1) Chemical composition of PM2.5 in four transport sectors.<br> (2) Time series of organic aerosol factors resolved by PMF&ME-2 in four transport sectors.<br> (3) Meteorological data corresponded to the ACSM and PMF&ME-2 data.<br> (4) f44 and f43 ratio in four transport sectors.</p>
Sagittal Balance in Children: Reference Values of the Sacral Slope for the Roussouly Classification and of the Pelvic Incidence for a New, Age-Specific Classification
<p>Raw data of the paper entitled "Sagittal Balance in Children: Reference Values of the Sacral Slope for the Roussouly Classification and of the Pelvic Incidence for a New, Age-Specific Classification", published on Applied Sciences</p>
Data from: Irregular forest structures originating after fire: an opportunity to promote alternatives to even-aged management in boreal forests
<p><span>1. Even-aged silviculture based on short-rotation clearcuts had severely altered boreal forests. Silvicultural alternatives (e.g., continuous cover or retention forestry) has the potential to restore and protect the habitats and functions of boreal forests. These alternatives are however often restricted to structurally complex old-growth forest, which are particularly threatened by anthropogenic disturbances. Increasing the use of alternatives to even-aged silviculture in early-successional stands could help recruit more structurally complex forests, with characteristics closer to the old-growth. In this article, we therefore evaluate the potential for silvicultural alternatives to even-aged management in boreal forests that burned less than a century ago.</span></p> <p><span>2. We analyzed 1085 field plots in a 243000 km<sup>2</sup> area situated in the boreal forest of eastern Canada. These plots burned 30 to 100 years before the survey and had not been subjected to previous or subsequent anthropogenic disturbance; they hence represent young primary forests. The main patterns of tree diameter distribution variation within the plots were identified using k-means clustering. Stand structure, tree species composition, and environmental variables that most explained the differences among the clusters were identified with a random forest model, and then compared using Kruskal-Wallis and Fisher's exact tests.</span></p> <p><span>3.</span> <span>The majority (>75 %) of the plots presented an irregular structure of stem diameters (i.e., non-normally distributed, with many small diameter trees). The understorey was generally dominated by black spruce (<em>Picea mariana</em> [Mill.] BSP), a shade-tolerant species. Irregular structures were observed in both forests of high and low productivity, implying that different processes (e.g., early regeneration, variable tree growth) can lead to observed early irregular structure. Regular structures were generally characterized by a higher productivity and abundance in hardwood species compared to the irregular structures. </span></p> <p><span>4. <em>Synthesis and application</em>: Many boreal forests of eastern Canada progress towards an irregular structure in the decades following the last stand-replacing fire. A substantial part of these early-successional forests may be suitable for alternatives to even-aged silviculture that better maintains habitats and functions of preindustrial boreal forests. </span></p>
Individual variation explains aging patterns in a cooperatively breeding bird, the long-tailed tit (Aegithalos caudatus)
<p><span><strong>1</strong>.</span><span> Alloparental care in cooperatively-breeding species may alter breeder age-specific survival and reproduction, and subsequently senescence. The helping behaviour itself might also undergo age-related change, and decisions to help in facultative cooperative breeders are likely to be affected by the individual condition.</span></p> <p><span><strong>2</strong>.</span><span> Helpers in long-tailed</span><span> tits (<em>Aegithalos caudatus</em>) assist relatives after failing to raise their own brood, with offspring from helped nests being more likely to recruit into the breeding population.</span></p> <p><span><strong>3</strong>.</span><span> Using data collected over 25 years, we examined the age-trajectories of survival and reproduction in adult long-tailed tits to determine how these were affected by the presence or absence of helpers, and how helper behaviour changed with age.</span></p> <p><span><strong>4</strong>.</span><span> There was evidence for increased reproductive performance with breeder age, but no effect of age on the probability of survival. We found no evidence of significant senescent decline in survival or reproductive performance, although individuals accrued less inclusive fitness in their last year of life. Lifetime reproductive success was positively related to both reproductive lifespan and body mass. Within a season, breeders that were assisted by helpers enjoyed greater reproductive success through enhanced offspring recruitment in the following year. We found no evidence that age affected an individual's propensity to help, or the amount of indirect fitness accrued through helping.</span></p> <p><span><strong>5</strong>.</span><span> We found a positive correlation between lifespan and multiple components of reproductive success, suggesting that individual variation in quality underpins age-related variation in fitness in this species. Helping decisions are driven by condition, and the lifetime inclusive fitness of immigrants was predicted by body mass. These findings further support individual heterogeneity in quality being a major driver for fitness gains across the life course of long-tailed tits.</span></p>
Subspecies and Distribution. O.c.cuniculusLinnaeus,1758—N,NE&EIberianPeninsula(Spain). O.c.algirusLoche,1858—S,SW&WIberianPeninsula(Spain,Portugal),NMorocco,NAlgeria(includingHabibasI). O.c.brachyotusTrouessart,1917—SFrance. O.c.cnossiusBate,1906—CreteI. O.c.habetensisCabrera,1923—Tanger-Tetouan-AlHoceimaRegion(NMorocco). O. c. huxleyi Haeckel, 1874 — Mediterranean Is (Balearic Is, Corsica, Sardinia, Sicily and Macaronesia (Azores, Madeira, and Canary Is). Original distribution after last Ice Age restricted to Iberian Peninsula, W France, and N Africa. Ancient introductions of the nominate subspecies probably during the Ro- man period have spread it throughout Europe, and now it is present in most of W, C & E Europe and the Mediterranean and Macaronesian Is (these mostly old introductions are also shaded on the map). During the 20" century it has been released into the steppes of the Black Sea in Ukraine and Russia (N Caucasus); introduced into Australia in 1788 and again in 1859 where it is now widespread; it is found on many Pacific Is, islands off the coast of South Africa and Namibia, and in New Zealand; successfully introduced only since 1936 into South America, nowadays with a limited range in Chile, Argentina, and Falkland Is, it is also present in the Caribbean Is (all these modern introductions not shaded in the map). Worldwide as domesticated forms. in Leporidae
Subspecies and Distribution. O.c.cuniculusLinnaeus,1758—N,NE&EIberianPeninsula(Spain). O.c.algirusLoche,1858—S,SW&WIberianPeninsula(Spain,Portugal),NMorocco,NAlgeria(includingHabibasI). O.c.brachyotusTrouessart,1917—SFrance. O.c.cnossiusBate,1906—CreteI. O.c.habetensisCabrera,1923—Tanger-Tetouan-AlHoceimaRegion(NMorocco). O. c. huxleyi Haeckel, 1874 — Mediterranean Is (Balearic Is, Corsica, Sardinia, Sicily and Macaronesia (Azores, Madeira, and Canary Is). Original distribution after last Ice Age restricted to Iberian Peninsula, W France, and N Africa. Ancient introductions of the nominate subspecies probably during the Ro- man period have spread it throughout Europe, and now it is present in most of W, C & E Europe and the Mediterranean and Macaronesian Is (these mostly old introductions are also shaded on the map). During the 20" century it has been released into the steppes of the Black Sea in Ukraine and Russia (N Caucasus); introduced into Australia in 1788 and again in 1859 where it is now widespread; it is found on many Pacific Is, islands off the coast of South Africa and Namibia, and in New Zealand; successfully introduced only since 1936 into South America, nowadays with a limited range in Chile, Argentina, and Falkland Is, it is also present in the Caribbean Is (all these modern introductions not shaded in the map). Worldwide as domesticated forms.
The datasets for the paper "Spatial and temporal distribution of lobate scarps in the lunar south polar region: Evidence for latitudinal variation of scarp geometry, kinematics and formation ages, continuous tectonic activity in the last 100 million years and seismically safe south pole Artemis human landing site" Geophysical Research Letters.
<p>This dataset provides the original data that were used for preparing the illustrations, figures and tables.</p>
Variations in immune parameters with age in a wild rodent population and links with survival
<p>Recent findings suggest that immune functions do not unidirectionally deteriorate with age but that a potentially adaptive remodelling, where functions of the immune system get down regulated while others get upregulated with age could also occur. Scarce in wild populations, longitudinal studies are yet necessary to properly understand the patterns and consequences of age variations of the immune system in the wild. Meanwhile, it is challenging to understand if the observed variations in immune parameters with age are due to changes at the within-individual level or to selective (dis)appearance of individuals with peculiar immune phenotypes. Thanks to a long-term and longitudinal monitoring of a wild Alpine marmot population, we aimed to understand within- and between-individual variation in the immune phenotype with age, in order to improve our knowledge about the occurrence and the evolutionary consequences of such age-variations in the wild. To do so, we recorded the age-specific leukocyte concentration and leukocyte profile in repeatedly sampled dominant individuals. We then tested whether the potential changes with age were attributable to within-individual variations and/or selective (dis)appearance. Finally, we investigated if the leukocyte concentration and profiles were correlated to the probability of death at a given age. The leukocyte concentration was stable with age, but the relative number of lymphocytes decreased, while the relative number of neutrophils increased, over the course of an individual's life. Moreover, between individuals of the same age, individuals with fewer lymphocytes but more neutrophils were more likely to die. Therefore, selective disappearance seems to play a role in the age variations of the immune parameters in this population. Further investigations linking age variations in immune phenotype to individual fitness are needed to understand whether remodelling of the immune system with age could or could not be adaptive.</p>
Table S1/2: Duration of swimming participation and age of subjects, Time of 200m swimming
<p>1. Duration of swimming participation and age of subjects</p> <p>2. Time of 200m swimming</p>
Data from: Ageing gracefully: physiology but not behaviour changes with age in a diving seabird
A higher proportion of long-lived animals die from senescence than short-lived animals, yet many long-lived homeotherms show few signs of physiological aging in the wild. This may, however, differ in long-lived diving homeotherms that frequently encounter hypoxic conditions and have very high metabolic rates. To examine aging within a long-lived diving homeotherm, we studied resting metabolism and thyroid hormones (N = 43), blood oxygen stores (N = 93), and foraging behaviour (N = 230) of thick-billed murres (Uria lomvia). Because murres dive exceptionally deep for their size and have a very high metabolism, we expected that aging murres would show signs of physiological senescence. We paid particular attention to resting metabolism as we argue that these maintenance costs reflect those experienced during deep dives. Blood oxygen stores (hematocrit), resting metabolic rate and thyroid hormone levels all declined significantly with age in incubating murres 3-30 years of age. In birds measured longitudinally three years apart, thyroid hormone levels and hematocrit were both significantly lower, suggesting progressive changes within individuals rather than selective disappearance of individuals with high metabolic rates. Within our longitudinal dataset, we found no effect of age on dive depth, dive shape, or behavioural aerobic dive limit. A meta-analysis of changes in resting metabolism with age across 15 animal species demonstrated that such declines are pervasive across most of the kingdom. The rate of decline was highest in species with high energy expenditure supporting a linkage between metabolism and senescence. Physiological changes occurred in tandem with advancing age in murres, but offset each other such that there was no detectable decline in behavioural performance.
Data from: Age and sex as compounding factors in the relationship between cardiac mitochondrial function and type 2 diabetes in the Nile Grass rat
[No abstract entered]
Data from: Premating isolation is determined by larval rearing substrates in cactophilic Drosophila mojavensis. X. Age-specific dynamics of adult epicuticular hyrdocarbon expression in response to different host plants
Analysis of sexual selection and sexual isolation in Drosophila mojavensis and its relatives has revealed a pervasive role of rearing substrates on adult courtship behavior when flies were reared on fermenting cactus in preadult stages. Here, we assessed expression of contact pheromones comprised of epicuticular hydrocarbons (CHCs) from eclosion to 28 days of age in adults from two populations reared on fermenting tissues of two host cacti over the entire life cycle. Flies were never exposed to laboratory food and showed significant reductions in average CHC amounts consistent with CHCs of wild-caught flies. Overall, total hydrocarbon amounts increased from eclosion to 14–18 days, well past age at sexual maturity, and then declined in older flies. Most flies did not survive past 4 weeks. Baja California and mainland populations showed significantly different age-specific CHC profiles where Baja adults showed far less age-specific changes in CHC expression. Adults from populations reared on the host cactus typically used in nature expressed more CHCs than on the alternate host. MANCOVA with age as the covariate for the first six CHC principal components showed extensive differences in CHC composition due to age, population, cactus, sex, and age × population, age × sex, and age × cactus interactions. Thus, understanding variation in CHC composition as adult D. mojavensis age requires information about population and host plant differences, with potential influences on patterns of mate choice, sexual selection, and sexual isolation, and ultimately how these pheromones are expressed in natural populations. Studies of drosophilid aging in the wild are badly needed.
Data from: Validity of bioelectrical impedance analysis in predicting total body water and adiposity among Senegalese school-aged children
Introduction: Childhood obesity is currently a serious public health challenge in developing countries. Therefore, an accurate assessment of adiposity is required. The objective of this study was to validate BIA prediction equations for the assessment of total body water and adiposity or percentage of body fat for the first time in Senegalese school-aged children. Methods: One-hundred-fifty-one (151) pupils who were 8-11 years old were randomly selected from four public schools in Dakar. The body composition measured by deuterium dilution method (DDM) was used as the reference method and compared to that predicted by BIA using a multi-frequency analyser. Stepwise backward multiple linear regression was performed to calculate TBW and %BF in a subsample, which were then validated it in the rest of the sample. The Bland and Altman approach was used to assess the agreement between the two methods (bias and limits of agreement). Results: FFM was higher in boys (24.6±6.9 kg) compared to girls (21.2±3.3 kg; P<0.001), and %BF was lower in boys (5.1±4.6 kg) compared to girls (5.3±3.8 kg; P<0.05). Overall, 11.3% of children were obese (%BF ≥25% in boys, and ≥30% in girls) and 4.6% were overweight/obese according to their BMI-z score (>+1). The equations developed were as follows: TBW=0.376(Height²/Z50)-0.470 (sex) +0.076(weight) +0.065(height)-2.28. %BF= -1.10(height²/Z50) +3.14(sex)+1.57(weight)-4.347. These specific equations showed good precision and a low and non-significant mean bias (0.11 kg, P=0.279; and 0.19 kg, P=0.764) for TBW and %BF, respectively. Conclusion: The newly developed equations can be used as an accurate and alternative tool for screening for obesity among African school-aged children in various settings
Elevation-Dependent Warming Identified During the Abrupt Shift at the Last Ice Age Termination
<p>The current Earth’s surface warming rate may increase with elevation, known as Elevation-Dependent Warming, which has profound environmental impacts on the fragile environments in high-elevation mountainous regions. However, Elevation-Dependent Warming has not been well constrained due to the short duration and sparse distribution of available instrumental data. Here we report quantitative paleotemperature reconstructions for three lakes within the elevational range of 1800–3800 m above sea level in the Hengduan Mountains, southeastern Tibetan Plateau, to show that abrupt warming occurred during ~14500–14000 years ago, and the warming rate was higher at higher elevations. We also find a prolonged cold interval from ~24000 to ~14000 years ago at high elevations, which coincides with the timing of the regional mountain glacier advances. We conclude that the observed Elevation-Dependent Warming was probably driven by the surface snow-albedo feedback caused by the rapidly shrinking mountain glaciers, which had a stronger influence at higher elevations.</p>
Supplementary material 2 from: Sturm U, Heyne E, Herrmann E, Arends B, Dieter A-L, Dorfman E, Drauschke F, Heller N, Kahn R, Kaiser K, Koch G, Kramar N, Mansilla Sánchez A, Mauelshagen F, Nadim T, Pell R, Petersen M, Schmidt-Loske K, Scholz H, Sterling C, Trischler H, Wagner S (2022) Anthropocenic Objects. Collecting Practices for the Age of Humans. Research Ideas and Outcomes 8: e89446. https://doi.org/10.3897/rio.8.e89446
Flyer: How to collect, store and curate objects in the Anthropocene? On participatory and digital collections.
Supplementary material 1 from: Sturm U, Heyne E, Herrmann E, Arends B, Dieter A-L, Dorfman E, Drauschke F, Heller N, Kahn R, Kaiser K, Koch G, Kramar N, Mansilla Sánchez A, Mauelshagen F, Nadim T, Pell R, Petersen M, Schmidt-Loske K, Scholz H, Sterling C, Trischler H, Wagner S (2022) Anthropocenic Objects. Collecting Practices for the Age of Humans. Research Ideas and Outcomes 8: e89446. https://doi.org/10.3897/rio.8.e89446
Flyer: What is an Anthropocenic Object? Transdisciplinary Perspectives on Natural, Cultural and Hybrid Objects
Supplementary material 4 from: Sturm U, Heyne E, Herrmann E, Arends B, Dieter A-L, Dorfman E, Drauschke F, Heller N, Kahn R, Kaiser K, Koch G, Kramar N, Mansilla Sánchez A, Mauelshagen F, Nadim T, Pell R, Petersen M, Schmidt-Loske K, Scholz H, Sterling C, Trischler H, Wagner S (2022) Anthropocenic Objects. Collecting Practices for the Age of Humans. Research Ideas and Outcomes 8: e89446. https://doi.org/10.3897/rio.8.e89446
Keynote Exhibiting the Anthropocene - and the Technosphere - means breaking away from established knowledge orders
Removal of senescent cells reduces the viral load and attenuates pulmonary and systemic inflammation in SARS-CoV-2-infected, aged hamsters
<p>Older age is one of the strongest risk factors for coronavirus disease 2019 (COVID-19) morbidity and mortality. In an older adult, the chronic accumulation of senescent cells can interfere with the immune system and accentuate inflammation. Here, we sought to determine whether age-associated cellular senescence contributes to the severity of COVID-19 by studying the well-established golden hamster model of severe acute respiratory syndrome coronavirus (SARS-CoV-2)-driven lung disease. We found that aged hamsters (22 months of age) accumulate senescent cells in the lungs and that the senolytic drug ABT-263 (a Bcl-2-family inhibitor) depletes these cells at baseline and during a SARS-CoV-2 infection (when the senescent cell count is typically elevated). Relative to young hamsters (2 months of age), aged hamsters had a greater viral load during the acute phase of infection and displayed higher levels of fibrosis and worse body weight recovery during the post-acute phase. Interestingly, early treatment with ABT-263 was associated with a significantly lower pulmonary viral load and an amelioration of COVID-19-like lung disease in aged (but not young) animals. ABT-263 treatment of aged animals was also associated with lower pulmonary and systemic levels of senescence-associated secretory phenotype factors. We conclude that the removal of senescent cells via treatment with a senolytic reduces the pathologic severity of SARS-CoV-2 infection in aged hamsters. As several senolytics have recently moved into early-stage clinical trials, our present findings have clear clinical relevance.</p>
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Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.