Distribution Of Ages Research Articles

The lords of the Amber Road: amber storage, distribution and processing in the early Iron Age and the La Tène period

Abstract In its early Iron Age heyday, amber items were in widespread use all along the Amber Road. The amount, type and deposition patterns of the amber accessories varied between the particular traditions, reaching lavish standards in some of the Hallstatt graves. As the disintegration of the Hallstatt communities north of the Sudetes disrupted the connection between the Baltic coast societies and the La Tène civilisation in the south, the early La Tène period saw a dramatic decline in the amber exchange and a significant decrease in the amount of amber deposited in archaeological contexts. While in the north the amber gradually fell into disfavour, the La Tène civilisation had never abandoned it. At the same time, its deposition contexts, distribution and symbolic load seem to have changed over time.

ARTERIAL STIFFNESS ESTIMATED BY BRACHIAL OSCILLOMETRY PREDICTS PROGRESSION TO HYPERTENSION IN PATIENTS WITH NORMAL AMBULATORY BLOOD PRESSURE

Objective: There is growing evidence that arterial stiffness can precede hypertension (HTN). This study aimed to assess the predictive value of Pulse Wave Velocity, estimated by brachial oscillometry (ePWV), for incident HTN in patients with initially normal ambulatory BP measurement (ABPM) after one year of follow-up. Design and method: This retrospective, observational, longitudinal study included all consecutive patients referred to a HTN Unit with suspected naïve HTN, without prior pharmacological treatment. EVA was defined according to ePWV exceeding the 90th percentile of its age group (Mobil-O-Graph, IEM®). Incident HTN was defined as ABPM at follow-up > 130/80 mmHg or prescription of antihypertensive medication. Standard clinical tests and ABPM were performed at baseline and after 12 months. Results: 223 consecutive patients with ABPM <130/80 mmHg entered the study, with 155 women (69.5%), a mean age of 47.9 years (±13.5), mean office BP of 128/73 (±13/8), mean ABPM of 118/73 (±7/5) mmHg and mean estimated PWV of 7.74 m/s (±1.7). At baseline, 51.1% of patients showed EVA. At follow-up, after a mean time of 1,1 years, 114 participants presented elevated ABPM. After adjustment for age, gender and ambulatory BP, presence of EVA at baseline was associated with progression to HTN at follow-up (OR:2,5;IC:1,4-4,6;p = 0.003). Furthermore, the pattern of PWV-EVA and incident HTA according to age were superimposable (Image). Arterial stiffness defined as ePWV > 10 m/s was also significantly associated with incident HTN, but showed a completely different distribution in age compared with incident HTN. Of note, arterial stiffness at follow-up was mainly determined by EVA at baseline (OR:6.1;IC:3.2-11.6;p = 0.001), but not by BP traits. Conclusions: Arterial damage, characterized as early vascular aging according to estimated PWV by brachial oscillometry, doubles the probability of sustained HTN one year after initial assessment in naïve patients with normal ABPM at baseline, independently of ambulatory and or office blood pressure at baseline. On the other hand, the main determinant of arterial stiffness at follow-up was elevated ePWV at baseline, but not blood pressure traits.

Uncertainty-aware blob detection with an application to integrated-light stellar population recoveries

Context. Blob detection is a common problem in astronomy. One example is in stellar population modelling, where the distribution of stellar ages and metallicities in a galaxy is inferred from observations. In this context, blobs may correspond to stars born in situ versus those accreted from satellites, and the task of blob detection is to disentangle these components. A difficulty arises when the distributions come with significant uncertainties, as is the case for stellar population recoveries inferred from modelling spectra of unresolved stellar systems. There is currently no satisfactory method for blob detection with uncertainties.Aims. We introduce a method for uncertainty-aware blob detection developed in the context of stellar population modelling of integrated-light spectra of stellar systems.Methods. We developed a theory and computational tools for an uncertainty-aware version of the classic Laplacian-of-Gaussians method for blob detection, which we call ULoG. This identifies significant blobs considering a variety of scales. As a prerequisite to apply ULoG to stellar population modelling, we introduced a method for efficient computation of uncertainties for spectral modelling. This method is based on the truncated Singular Value Decomposition and Markov chain Monte Carlo sampling (SVD-MCMC).Results. We applied the methods to data of the star cluster M 54. We show that the SVD-MCMC inferences match those from standard MCMC, but they are a factor 5–10 faster to compute. We apply ULoG to the inferred M 54 age/metallicity distributions, identifying between two or three significant, distinct populations amongst its stars.

River- and Sex-Specific Annual Survival Rates of Mature Anadromous Alewife (Alosa pseudoharengus)

During multiple annual spawning runs from 2013 to 2021, over 9,000 mature anadromous alewife (Alosa pseudoharengus A. Wilson, 1811) were monitored with passive integrated transponders (PITs) in four rivers of the Chignecto Isthmus, Bay of Fundy, Canada. A subsample of 384 individuals tagged during 2016–2019 were aged from 3 to 6 years (mean ± SD; 4.2 ± 0.7 years, n = 232, males; 4.5 ± 0.7 years, n = 152, females). Biotelemetry revealed that one unsexed individual survived seven years post tagging, possibly making it 10–13 years old. Return rates varied among the rivers, with the lowest rates in the most anthropogenically impacted river. Biotelemetry and ageing data were used to estimate apparent annual survival rates ranging from 0.25 to 0.50 depending on the river and the year. Based on capture-mark-recapture (CMR) analysis of biotelemetry data from the three less impacted rivers, the estimated overall annual survival was 0.396, total instantaneous mortality (Z) was 0.93, and future life expectancy from time of release was 1.08 years. Frequency distribution of ages 4–6 for alewife pooled from all four study rivers estimated a lower annual survival rate of 0.301, Z = 1.20, and a future life expectancy of 0.83 years. The biotelemetry detection rates were 0.89–0.98 but varied depending on the river and the year, with the lowest rates in one river during 2017-2018 possibly related to a malfunctioning tide gate preventing upstream fish passage and subsequent detection. Based on CMR, males had a higher survival rate compared to females, which translated into an overall mean survival increase of 0.05. Alewife survivorship in our study highlighted that a limited ecosystem-based management period is required to mitigate river connectivity and mortality issues to avoid loss of population cohorts and decrease the risk of extirpation.

A light scatter based model relating erythrocyte vesiculation to lifetime in circulation.

Methods for measuring erythrocyte age distribution are not available as a simple analytical tool. Most of them utilize the fluorescence or radioactive isotopes labeling to construct the age distribution and support physicians with aging indices of donor's erythrocytes. The age distribution of erythrocyte may be a useful snapshot of patient state over 120-days period of life. Previously, we introduced the enhanced assay of erythrocytes with measurement of 48 indices in four categories: concentration/content, morphology, aging and function (10.1002/cyto.a.24554). The aging category was formed by the indices based on the evaluation of the derived age of individual cells. The derived age does not exactly mean the real age of erythrocytes and its evaluation utilizes changes of cellular morphology during a lifespan. In this study, we are introducing the improved methodological approach that allows us to retrieve the derived age of individual erythrocytes, to construct the aging distribution, and to reform the aging category consisting of eight indices. The approach is based on the analysis of the erythrocyte vesiculation. The erythrocyte morphology is analyzed by scanning flow cytometry that measures the primary characteristics (diameter, thickness, and waist) of individual cells. The surface area (S) and sphericity index (SI) are calculated from the primary characteristics and the scattering diagram SI versus S is used in the evaluation of the derived age of each erythrocyte in a sample. We developed the algorithm to evaluate the derived age that provides eight indices in the aging category based on a model using light scatter features. The novel erythrocyte indices were measured for simulated cells and blood samples of 50 donors. We determined the first-ever reference intervals for these indices.

Assessing Vulnerability of Regional-Scale Aquifer-Aquitard Systems in East Gulf Coastal Plain of Alabama by Developing Groundwater Flow and Transport Models

Groundwater vulnerability assessment helps subsurface water resources management by providing scientific information for decision-makers. Rigorous, quantitative assessment of groundwater vulnerability usually requires process-based approaches such as groundwater flow and transport modeling, which have seldom been used for large aquifer-aquitard systems due to limited data and high model uncertainty. To quantify the vulnerability of regional-scale aquifer-aquitard systems in the East Gulf Coastal Plain of Alabama, a three-dimensional (3D) steady-state groundwater flow model was developed using MODFLOW, after applying detailed hydrogeologic information to characterize seven main aquifers bounded by aquitards. The velocity field calibrated by observed groundwater heads was then applied to calculate groundwater age and residence time for this 3D aquifer-aquitard system via backward/forward particle tracking. Radioactive isotope data (14C and 36Cl) were used to calibrate the backward particle tracking model. Results showed that shallow groundwater (<300 ft below the groundwater table) in southern Alabama is mainly the Anthropocene age (25–75 years) and hence susceptible to surface contamination, while the deep aquifer-aquitard systems (700 ft or deeper below the groundwater table) contain “fossil” waters and may be safe from modern contamination if there is no artificial recharge/discharge. Variable horizontal and vertical vulnerability maps for southern Alabama aquifer-aquitard systems reflect hydrologic conditions and intermediate-scale aquifer-aquitard architectures in the regional-scale models. These large-scale flow/transport models with coarse resolutions reasonably characterize the broad distribution and vertical fluctuation of groundwater ages, probably due to aquifer-aquitard structures being captured reliably in the geology model. Parameter sensitivity analysis, vadose zone percolation time, wavelet analysis, and a preliminary extension to transient flow were also discussed to support the aquifer vulnerability assessment indexed by groundwater ages for southern Alabama.

The long view of vaccination to secure the future

The long view of vaccination to secure the future

The Systemic Availability of Indispensable Amino Acids from Orally Ingested Algal and Legume Protein in Young Children at Risk of Environmental Enteric Dysfunction

BackgroundThe digestion and absorption of ingested protein may be reduced in children with environmental enteric dysfunction (EED), reducing systemic amino acid availability for protein synthesis with resultant growth faltering. This has not been directly measured in children with EED and associated growth faltering. ObjectivesTo evaluate the systemic availability of algal (spirulina) and legume (mung bean) indispensable amino acids (IAAs) in children with EED. MethodsIndian children (18–24 mo) from urban slums were assigned to EED (n = 24) or no-EED (control, n = 17) groups based on the lactulose rhamnose test, where the lactulose rhamnose ratio cutoff for diagnosing EED (≥0.068) was the mean + 2SD of its distribution in healthy, age-, and sex-matched children of high socioeconomic status. Fecal biomarkers of EED were also measured. Systemic IAA availability was calculated from the plasma: meal IAA enrichment ratio for each protein. True ileal mung bean IAA digestibility was measured by the dual isotope tracer method using spirulina protein as reference. Co-administration of free 13C6-phenylalanine allowed for estimating true ileal phenylalanine digestibility of both proteins, and a phenylalanine absorption index. ResultsThere was no significant difference (independent t-test) in the systemic IAA availability from spirulina or mung bean protein between EED and no-EED groups. There was no between-group difference in true ileal phenylalanine digestibility and its absorption index, or in mung bean IAA digestibility. ConclusionsThe systemic IAA availability of algal and legume protein, or the latter’s IAA/phenylalanine digestibility, is not significantly reduced in children with EED and does not correlate with linear growth.This study was registered in Clinical Trials Registry of India (CTRI) with registration number: CTRI/2017/02/007921.

0526 Effect of Body Position and Sleep State on Sleep Disordered Breathing Distribution in Infants Ages 6 to 12 months

Abstract Introduction The effect of body position and sleep state on events distribution in infants ages 6 to 12 months needs further study. We aimed to study this distribution and determine the difference of body position in infants with and without sleep disordered breathing. Methods This was a single center, retrospective study that included infants ages 6 to 12 months who were evaluated for suspected sleep disordered breathing and underwent a full overnight polysomnography in an academic sleep disorders center over a period of 10 years. Infants with ages 6 to 12 months with obstructive sleep apnea hypopnea index (OAHI) and central apnea index (CAI) ≥ 1 (sleep disordered breathing [SDB] group) were compared with infants with normal AHI who represented the control group (CG). Total OAHI, CAI, apnea hypopnea index (AHI) in different body positions, rapid eye movement (REM), and Non-REM sleep were collected. Results A total of 36 infants had SDB and 18 infants had normal AHI. The median age was not significantly different between both groups with a median age of 10 months (IQR 7.75-11) in SDB group and 8.5 months in CG (IQR 7.25- 10.00) (p=0.258). Male sex was predominant in both groups (58.3% in SDB group and 61.1% in CG). There were no significant differences between both groups in the BMI, median total sleep time, REM% sleep time, and Non-REM% sleep time. The supine sleep time in the SDB group [258.90 minutes (IQR 149.35-381.25)] was significantly higher than the supine sleep time in the CG [165.90 minutes (IQR 54.55 to 285.05)] (p=0.035). In the SDB group, REM AHI [8.55 (IQR 5.02 – 15.25] was significantly higher than Non-REM AHI [0.50 (IQR 0.30-1.20)] (p< 0.001). In the SDB group, there were no significant differences in the supine vs. off-supine distribution of respiratory events. Conclusion Obstructive and central respiratory events in infants ages 6 to 12 months occurred predominantly in REM sleep compared to Non-REM sleep. Infants with SDB significantly spent more time in supine position when compared to infants without SDB but the respiratory events distribution in infants with SDB did not have a significant positional distribution. Support (if any)

Artificial intelligence to assist specialists in the detection of haematological diseases

Artificial intelligence, particularly the growth of neural network research and development, has become an invaluable tool for data analysis, offering unrivalled solutions for image generation, natural language processing, and personalised suggestions. In the meantime, biomedicine has been presented as one of the pressing challenges of the 21st century. The inversion of the age pyramid, the increase in longevity, and the negative environment due to pollution and bad habits of the population have led to a necessity of research in the methodologies that can help to mitigate and fight against these changes.The combination of both fields has already achieved remarkable results in drug discovery, cancer prediction or gene activation. However, challenges such as data labelling, architecture improvements, interpretability of the models and translational implementation of the proposals still remain. In haematology, conventional protocols follow a stepwise approach that includes several tests and doctor-patient interactions to make a diagnosis. This procedure results in significant costs and workload for hospitals.In this paper, we present an artificial intelligence model based on neural networks to support practitioners in the identification of different haematological diseases using only rutinary and inexpensive blood count tests. In particular, we present both binary and multiclass classification of haematological diseases using a specialised neural network architecture where data is studied and combined along it, taking into account the clinical knowledge of the problem, obtaining results up to 96% accuracy for the binary classification experiment. Furthermore, we compare this method against traditional machine learning algorithms such as gradient boosting decision trees and transformers for tabular data. The use of these machine learning techniques could reduce the cost and decision time and improve the quality of life for both specialists and patients while producing more precise diagnoses.

What’s in an age? Calculation and interpretation of ages and durations from U-Pb zircon geochronology of igneous rocks

Accurate assessment of the duration of zircon crystallization within igneous rocks is critical for constraining the time scales of magmatic evolution and storage, which have important implications for our understanding of magmatic fluxes and volcanic hazards. However, estimation of crystallization durations from finite geochronologic data sets is difficult and typically relies on numerous implicit assumptions. In this contribution, we evaluate these assumptions and provide recommendations for better interpretation of crystallization durations from individual samples by developing a simplified theoretical framework to relate zircon growth, nucleation, and armoring rates to zircon ages. We first investigate single zircon analyses and show that ages produced with methods that integrate the entire grain or grain fragments (e.g., chemical abrasion−isotope dilution−thermal ionization mass spectrometry [CA-ID-TIMS]) are inevitably biased toward the second half of the zircon growth interval, while subsampling of grains via microbeam approaches will only capture the majority of the zircon crystallization duration when the microbeam spot size is less than ∼25% of the zircon minor axis, and the analytical uncertainty of the measurement is less than ∼20% of the duration over which the individual zircon grew. We subsequently investigate the distribution of zircon mean ages produced through various combinations of zircon growth rate, nucleation rate, and the probability of zircon being armored by major phases. We show that zircon age distributions cannot be directly predicted from the rate of zircon mass crystallized, as many combinations of growth, nucleation, and armoring rates result in distinct age distributions, yet they produce nearly identical mass crystallization rates. Finally, we develop two equations that can be used to constrain the duration of crystallization observed within individual samples. In scenarios where the observed age dispersion is consistent with the reported analytical uncertainties, the first equation can be used to estimate the maximum duration. Otherwise, when the measured zircon population is overdispersed, a second equation constrains the minimum duration of zircon crystallization.

Young but fading radio sources: searching for remnants among compact steep-spectrum radio sources

ABSTRACT The incidence of young but fading radio sources provides important information on the life cycle of radio emission in radio-loud active galactic nuclei. Despite its importance for constraining the models of radio source evolution, there are no systematic studies of remnants in complete samples of young radio sources. We report results of the study of 18 compact steep-spectrum (CSS) radio sources, selected from the statistically complete B3-VLA (Very Large Array) CSS sample, characterized by a steep optically thin spectrum (α ≥ 1.0) and no core detection in earlier studies. Our deep multifrequency VLA, pc-scale Very Long Baseline Array, and enhanced Multi Element Remotely Linked Interferometer Network (e-MERLIN) observations allowed us to locate the core component in 10 objects. In three CSS sources, there is no clear evidence of present-time active regions, suggesting that they are likely in a remnant phase. Among sources with core detection, we find three objects that have no clear active regions (hotspots) at the edges of the radio structure, suggesting that the radio emission may have just restarted. Our results support a power-law distribution of the source ages, although the poor statistics prevents us from setting solid constraints on the percentage of remnants and restarted sources in subpopulations of radio sources.

The emerging role of lysine succinylation in ovarian aging

BackgroundOvarian aging is a process of decline in its reserve leading to ovary dysfunction and even reduced health quality in offspring. However, aging-related molecular pathways in the ovary remain obscure. Lysine succinylation (Ksuc), a newly post-translational modification (PTM), has been found to be broadly conserved in both eukaryotic and prokaryotic cells, and associated with multiple pathophysiological processes. There are no relevant reports revealing a link between the molecular mechanisms of ovarian aging and Ksuc.MethodsThe level of Ksuc in ovaries of aged and premature ovarian insufficiency (POI) mice were detected by immunoblotting and immunohistochemical. To further explore the role of Ksuc in ovarian aging, using in vitro mouse ovary tissue culture and an in vivo mouse model with changed Ksuc level.ResultsIncreased Ksuc in ovaries of aged and POI mice and distribution of Ksuc in various types of mice ovarian cells and the high level of Ksuc in granulosa cells (GCs) were revealed. Histological assessments and hormone levels analyses showed that the high Ksuc level down-regulated the ovarian index and the anti-Müllerian hormone (AMH) and estrogen levels, and increased follicular atresia. Moreover, in the high Ksuc groups, the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) intensities and the expression of Cleaved-caspase-3 increased and the expression of B-cell lymphoma-2 (Bcl-2) decreased together with positively-expressed P21, an aging-related marker. These results suggest that ovarian aging is likely associated with alteration in Ksuc.ConclusionThe present study has identified Ksuc in mouse ovary and found that high Ksuc level most likely contributes to ovarian aging which is expected further investigation to provide new information for delaying physiological ovarian aging and treating pathological ovarian aging.

Numerical simulations of the flow of a kerosene gel: Effects of thixotropy and shear-thinning

The ability of a gel to act like a solid-like material at rest and flow like a liquid when sheared can be very useful in propulsion system. Numerical simulation of the flow of gel fuels can be used as a reference to assist experimental studies and applications of these materials. Non-linear rheological effects such as shear thinning, yield stress, thixotropy and viscoelasticity can create difficulties in the formulation and in the numerical investigations. This paper uses a thixotropic shear-thinning constitutive relationship while using a second-order kinetic equation for the structural parameter, where the Carreau–Yasuda model is used for a 5% organic kerosene gel. We study the simple shear flow to verify the accuracy of the numerical method, and the impact of the constitutive parameters on the apparent viscosity as a function of shear rate. To look at the thixotropic flow in more complex flows, we initially study the pipe flow of an organic kerosene gel for different pumping conditions. After performing a parametric study, we find that the thixotropy of the gel strongly affects the shear history, that is, the nonuniform aging distribution. The destruction of the microstructure can be accelerated by adjusting the flow intensity and the model parameters, but it seems that it is difficult to arrive at the equilibrium state within the time scale of the propulsion system; this poses a challenge to the design of the system.

The socioeconomic consequences of population ageing: aspects of modern challenges in the Russian Federation

Purpose: the article summarizes the key characteristics of the population ageing phenomenon and identifies the channels through which it has an impact on the demographic crisis parameters as well as the socioeconomic growth of the country.Methods: the study is based on tracking the consequences associated with the phenomenon of population ageing. Simultaneously, computational and graphical methods, comparative and retrospective analysis of the sex and age pyramids, expert and empirical assessment of the trends in the structure of the population older than 60-65 years, as well as its economic burden per 1,000 able-bodied people, were used.Results: the main parameters of the socioeconomic impacts of population ageing are determined. Age limits and essential features of this phenomenon are revealed. The forecast trend of socioeconomic parameters of population ageing is supported by the SWOT analysis matrix, and a conceptual model for the implementation of systematic adjustment measures for the ongoing demographic crisis is proposed.Conclusions and Relevance: the article demonstrates that population ageing is not a fundamental socioeconomic problem that endangers the well-being of the population over working age. However, it has many negative consequences for the socioeconomic growth of the country that are still being researched; the real threats come not from population ageing as such, but from the existing disproportion in the workload of the population over 60-65 years old per 1,000 able-bodied population. Despite the relative parameters of the ageing trend in Russia, in the future, the life expectancy of the population will be 73.58-75.03 years.

Assembly of the Variscan Orogenic Wedge in the Bohemian Massif: Monazite U‐Pb Geochronology of the Tectonic Events Recorded in Saxothuringian Metasediments

AbstractThe geochronology of metasediments incorporated to orogenic wedges provides an important key in understanding the early evolution of collisional systems. This study reveals the timing of Variscan processes in the Saxothuringian orogenic wedge, reflecting transition from oceanic to continental subduction and collision. In situ monazite U‐Pb geochronology and Rare Earth Elements (REE) geochemistry were performed in the Erzgebirge Crystalline Complex on phyllites and micaschists surrounding the ultra‐high‐pressure (UHP) core of the Erzgebirge dome. The resulting ages and REE patterns were linked to the individual tectonometamorphic events and revealed that the hanging‐wall phyllites experienced prograde metamorphism around ∼350 Ma, followed by exhumation at ∼345–340 Ma. The oldest age (∼339 Ma) recorded in garnet cores in the foot‐wall micaschists is considered as an upper age limit for their prograde metamorphism, while matrix monazite ages of ∼330 Ma reflect a significant resetting of the monazite age system. Spatial distribution of metamorphic isograds and ages indicates a phase of accretion of continental material resulting in an inverted metamorphic field gradient in the wedge between ∼360 and ∼340 Ma. This phase was followed by exhumation of a significant portion of buoyant subducted continental material leading to massive ductile thinning of the wedge around ∼335 Ma. Finally, a late Variscan intracontinental deformation was responsible for heterogeneous reactivation and final exhumation of the wedge at ∼330 Ma. It is newly shown that the Saxothuringian wedge can be divided into a younger inner part, formed by micaschists and UHP rocks, and an older outer part, formed by phyllites.

Thermo‐Kinematic Evolution of the Eastern European Alps Along the TRANSALP Transect

AbstractThe eastern European Alps are shaped by the indentation of Adria into Europe. Recent tomography, depicting detached slab fragments, has been interpreted as evidence of continuous southward subduction of European lithosphere, contrary to an often‐invoked subduction polarity reversal. Orogen‐scale exhumation, driven by rock displacement along active faults, may reflect subduction polarity within the framework of doubly‐vergent Coulomb wedge theory, provided the absence of rheological contrasts across the colliding plates. Low‐temperature thermochronology can evaluate crustal cooling in response to changes in tectonic and erosional boundary conditions. This study investigates the consistency of observed crustal re‐organization, exhumation, and mantle processes in the Eastern Alps. Thermo‐kinematic forward models driven by reconstructions of crustal shortening along the TRANSALP geophysical transect were subjected to variations in shortening rates, thermophysical parameters, and topographic evolution, supplemented by new fission‐track data. The thermo‐kinematic models reproduce: (a) the orogen‐scale structural geometry, (b) the distribution of thermochronometer ages, (c) observed time‐temperature paths, and (f) the present‐day surface heat flux. Results suggest that exhumation is driven by rock displacement along active faults without the need to involve mantle‐driven buoyancy forces. Taken together, the results identify two possible scenarios: if the Tauern Ramp is a retro‐thrust and the southward shift of deformation in the Southern Alps is a response to new Coulomb‐wedge conditions, then our results support a Mid‐Miocene reversal of the subduction polarity. Alternatively, crustal deformation does not reflect mantle processes entailing a high degree of inter‐plate decoupling.

Influence of telomerase activity and initial distribution on human follicular aging: Moving from a discrete to a continuum model.

A discrete model is proposed for the temporal evolution of a population of cells sorted according to their telomeric length. This model assumes that, during cell division, the distribution of the genetic material to daughter cells is asymmetric, i.e. chromosomes of one daughter cell have the same telomere length as the mother, while in the other daughter cell telomeres are shorter. Telomerase activity and cell death are also taken into account. The continuous model is derived from the discrete model by introducing the generational age as a continuous variable in [0,h], being h the Hayflick limit, i.e. the number of times that a cell can divide before reaching the senescent state. A partial differential equation with boundary conditions is obtained. The solution to this equation depends on the initial telomere length distribution. The initial and boundary value problem is solved exactly when the initial distribution is of exponential type. For other types of initial distributions, a numerical solution is proposed. The model is applied to the human follicular growth from preantral to preovulatory follicle as a case study and the aging rate is studied as a function of telomerase activity, the initial distribution and the Hayflick limit. Young, middle and old cell-aged initial normal distributions are considered. In all cases, when telomerase activity decreases, the population ages and the smaller the h value, the higher the aging rate becomes. However, the influence of these two parameters is different depending on the initial distribution. In conclusion, the worst-case scenario corresponds to an aged initial telomere distribution.

Analysis of Spatial Distribution of Aging and Internal Migration in the Counties of Country

Objectives Considering the migration age pattern and the aging trend in Iran, this study aims to investigate the migration effect on the aging spatial distribution of the country during 2006-2016. Methods & Materials This study is a secondary and descriptive-analytical analysis. The source used is the data of the general population and housing census and the analysis unit is the counties of the country. Pearson correlation and analysis of variance in SPSS software, version 22 were used to analyze the data and geographic information system (GIS) was used to display spatial distribution maps. Results The study of the migration process in the cities showed that the immigrant-first cities have gone towards aging by losing their young population, while the young cities are mostly receiver-migrant. As a result, the proportion of elder cities is increasing every year. The correlation between the net migration rate and the aging index indicates the inverse relationship (-0.363, -0.303, and -0.216) of these two variables during all periods; as the net migration rate increases, the aging index decreases. The results of the analysis of variance also showed the net migration rate at the county level is significantly different (P = 0.000). The spatial distribution also showed that immigrant-first cities in the western and northwestern regions have a higher rate of aging compared to other regions. Conclusion According to the research question, it should be said that the spatial pattern of aging in the population of Iran according to the studied indicators is scattered in clusters and the population of Iran is transitioning from middle age to old age.

A 5500-year record of coastal dune evolution along the shores of Lake Michigan in the North American Great Lakes: The relationship of lake-level fluctuations and climate

Dune fields line much of the ∼1750-km long shore of Lake Michigan that extends from northwestern Indiana, north along the west coast of Lower Michigan, and west across southern Upper Michigan. Numerous geomorphic studies at specific sites or defined coastal reaches have demonstrated that dune formation began during the Nipissing maximum (∼5500–4500 calendar year Before Present (cal yr BP) and continued episodically to the present. Dune formation in these geographically confined areas is linked mostly to high lake stages and periods of increased storminess. Some recent research has also invoked drought as a potential causal mechanism on a site-specific basis. Although more than 250 collective absolute carbon-14 (14C) and optically stimulated luminescence (OSL) ages have been acquired in these many studies, a comprehensive statistical assessment of this robust dataset has yet to be conducted to reconstruct a full chronological reconstruction of dune evolution.This study statistically analyzes the dataset of all known OSL (118) and 14C ages (175) acquired directly from sand dunes. Application of a kernel density estimation (KDE) algorithm function to both datasets revealed the temporal patterns in the ages. Analysis of OSL ages indicates three major periods of dune growth, beginning between ∼5.0 and 3.8 ka during the Nipissing high stand and subsequent regression. The second phase occurred between ∼3.0 and 2.0 ka during the Algoma high stand and regression. Finally, the most recent interval of dune growth transpired between ∼1.3 and 0.8 ka in the aftermath of a high lake stage at ∼1.7 ka and another, shorter peak in lake level at ∼1.0 ka. These findings indicate that major pulses of dune building mostly occur during lake regressions. They also correspond to the relatively warmer and drier conditions of the Holocene Climate Optimum, Roman Climate Optimum, and Medieval Warm Period, respectively, as well as periods of relative drought in the region. These associations indicate that drier conditions may have contributed to dune activation.Plotting of 14C data reveals no single variable, such as stability or burial, explains the timing of the four peaks in the kernel distribution of ages derived from organic remains. Intervals of higher 14C age frequencies occurred between ∼4500 and 3800 cal yr BP, ∼3500 and 2600 cal yr BP, ∼2300 and 1600 cal yr BP, and ∼700 and 200 cal yr BP. The peak at ∼4200 cal yr BP corresponds with a similar OSL pattern, indicating that 14C ages derived from weakly developed Entisols during this interval reflects their burial by eolian sand. Peaks in 14C densities within the latter intervals at ∼3200, ∼1800, and ∼400 cal Yr BP align with distinct drops in the OSL distribution. This pattern indicates that 14C ages from these intervals reflect episodes of stability and soil formation subsequent to episodes of dune building. Although this study demonstrates the general patterns of dune growth and stability, local variations in behavior likely occurred.