The Radium triplet 226Ra, 228Ra, 224Ra in saline deep water - a valuable information source

The occurrence of enhanced concentration of the radium triplet 226Ra, 228Ra and 224Ra is a frequently observed property of highly saline anoxic deep water as used e.g. in geothermal plants. In the present study we develop a model to explain the observed activity levels in the brines. The model considers processes at the rock-fluid interface of the aquifer like alpha recoil, sorption and surface precipitation and is implemented by means of a Monte Carlo simulation. The outcomes of the simulations indicate the dominating role of fine-grained constituents of the reservoir rock, e.g. claystone with enhanced specific activities of the natural decay chains. Mass fractions of such material in the order of a few percent are sufficient to result in radium fluid concentrations >1 Bq l-1. Also a generally valid relation between the Th/U ratio in the aquifer rock and the 228Ra/226Ra activity ratio in the fluid was found. This link improves the agreement between radium fluid data and the mean Th/U ratio of the Earth's crust. The 224Ra/228Ra fluid ratios reflect the transport time from the location of last radium release to the sampling point. The model findings were applied to a well investigated aquifer used in a geothermal plant in the North German Basin. An eight component system of the aquifer rock was established as the basis for the simulation of the radium concentrations in the deep fluid. The comparison between simulation and fluid analyses revealed a degree of radium sorption of about 50 %, which is necessary to match the model's results with the measurements. On the other hand, the 228Ra/226Ra fluid ratio of the brine was well reproduced by the simulation, showing the suitability of the model even in complex heterogeneous reservoirs. From the 224Ra/228Ra fluid ratios a transition from pore-to fracture-guided transport < 10 m distance from the production well is suggested. Precipitates from such deep fluids occurring after changes of the thermodynamic conditions are able to accumulate radium isotopes in Ba/Sr-sulphate phases. The time dependence of the radioactive disequilibrium between 226Ra, 228Ra and its child 228Th in such scales is described by a mathematical model and is applied to two different uptake models. Based on this approach, age determinations on precipitates found in different components of a geothermal plant are conducted. They reveal the triggering of scale formation due to modifications in the plant. The results are suitable for drawing conclusions about the operation of the system, which result in a reduction in the amount of scale and a reduction in downtimes.

MRI segmentation of tooth tissue in age prediction of sub-adults - a new method for combining data from the 1st, 2nd, and 3rd molars

PURPOSE

We aimed to establish a model combining MRI volume measurements from the 1st, 2nd and 3rd molars for age prediction in sub-adults and compare the age prediction performance of different combinations of all three molars, internally in the study cohort.

MATERIAL AND METHOD

We examined 99 volunteers using a 1.5 T MR scanner with a customized high-resolution single T2 sequence. Segmentation was performed using SliceOmatic (Tomovision©). Age prediction was based on the tooth tissue ratio (high signal soft tissue + low signal soft tissue)/total. The model included three correlation parameters to account for statistical dependence between the molars. Age prediction performance of different combinations of teeth for the three molars was assessed using interquartile range (IQR).

RESULTS

We included data from the 1st molars from 87 participants (F/M 59/28), 2nd molars from 93 (F/M 60/33) and 3rd molars from 67 (F/M 45/22). The age range was 14-24 years with a median age of 18 years. The model with the best age prediction performance (smallest IQR) was 46-47-18 (lower right 1st and 2nd and upper right 3rd molar) in males. The estimated correlation between the different molars was 0.620 (46 vs. 47), 0.430 (46 vs. 18), and 0.598 (47 vs. 18). IQR was the smallest in tooth combinations including a 3rd molar.

CONCLUSION

We have established a model for combining tissue volume measurements from the 1st, 2nd and 3rd molars for age prediction in sub-adults. The prediction performance was mostly driven by the 3rd molars. All combinations involving the 3rd molar performed well.

Predicting chronological age of 14 or 18 in adolescents: integrating dental assessments with machine learning

AIM

Age estimation plays a critical role in personal identification, especially when determining compliance with the age of consent for adolescents. The age of consent refers to the minimum age at which an individual is legally considered capable of providing informed consent for sexual activities. The purpose of this study is to determine whether adolescents meet the age of 14 or 18 by using dental development combined with machine learning.

METHODS

This study combines dental assessment and machine learning techniques to predict whether adolescents have reached the consent age of 14 or 18. Factors such as the staging of the third molar, the third molar index, and the visibility of the periodontal ligament of the second molar are evaluated.

RESULTS

Differences in performance metrics indicate that the posterior probabilities achieved by machine learning exceed 93% for the age of 14 and slightly lower for the age of 18.

CONCLUSION

This study provides valuable insights for forensic identification for adolescents in personal identification, emphasizing the potential to improve the accuracy of age determination within this population by combining traditional methods with machine learning. It underscores the importance of protecting and respecting the dignity of all individuals involved.

A comparison of estimated age based on pulp volume from cone beam computed tomography (CT) images and panoramic radiography data with chronological age

This retrospective study was conducted to evaluate different methods for dental age estimation in children and to examine the feasibility of using cone beam computed tomography (CBCT) data for age estimation. A total of 200 radiographic records (both digital panoramic radiographs and CBCTs) were acquired from 100 children aged 9 to 16 years, all taken on the same dates. Radiographic data was acquired from archived records and included both panoramic radiography and CBCT data belonging to the same individual. CBCT was used when panoramic radiographic data was insufficient. The pulp volume and pulp/tooth volume ratio of the left first molar teeth in the mandible were calculated from the CBCT data using MIMICS software. In addition, age was estimated by the Demirjian and Willems methods from data obtained from panoramic radiography images. Statistical analyses and linear regression analysis were performed as necessary. There was a statistically significant difference between the mean difference between the Demirjian method and chronological age, and between the Willems method and chronological age (p < 0.001). Statistically significance was achieved in a linear regression model created from pulp volume (R2 = 0.098) and pulp/tooth volume ratio (R2 = 0.395) data for the estimated dental age analysis (p < 0.001) and a negative correlation was observed with chronological age. When compared estimated dental age from CBCT data with chronological age, the pulp/tooth volume ratio method yielded results closer to chronological age than using only pulp volume data. When considering both panoramic radiographic age estimation methods and age estimation methods using CBCT data, we found that the results obtained with the Willems method, a panoramic radiographic age estimation technique, provided the closest results to the chronological age. More contributions should be made to the literature regarding the feasibility of age estimation using pulp and tooth volume as an alternative method.

Efficacy of the methods of age determination using artificial intelligence in panoramic radiographs - a systematic review

The aim of this systematic review is to analyze the literature to determine whether the methods of artificial intelligence are effective in determining age in panoramic radiographs. Searches without language and year limits were conducted in PubMed/Medline, Embase, Web of Science, and Scopus databases. Hand searches were also performed, and unpublished manuscripts were searched in specialized journals. Thirty-six articles were included in the analysis. Significant differences in terms of root mean square error and mean absolute error were found between manual methods and artificial intelligence techniques, favoring the use of artificial intelligence (p < 0.00001). Few articles compared deep learning methods with machine learning models or manual models. Although there are advantages of machine learning in data processing and deep learning in data collection and analysis, non-comparable data was a limitation of this study. More information is needed on the comparison of these techniques, with particular emphasis on time as a variable.

Application of entire dental panorama image data in artificial intelligence model for age estimation

BACKGROUND

Accurate age estimation is vital for clinical and forensic purposes. With the rapid advancement of artificial intelligence(AI) technologies, traditional methods relying on tooth development, while reliable, can be enhanced by leveraging deep learning, particularly neural networks. This study evaluated the efficiency of an AI model by applying the entire panoramic image for age estimation. The outcome performances were analyzed through supervised learning (SL) models.

METHODS

Total of 27,877 dental panorama images from 5 to 90 years of age were classified by 2 types of grouping. In type 1 they were classified by each age and in type 2, applying heuristic grouping, the age over 20 years were classified by every 5 years. Wide ResNet (WRN) and DenseNet (DN) were used for supervised learning. In addition, the analysis with ± 3 years of deviation in both types were performed.

RESULTS

For the DN model, while the type 1 grouping achieved an accuracy of 0.1016 and F1 score of 0.058, the type 2 achieved an accuracy of 0.3146 and F1 score of 0.2027. Incorporating ± 3years of deviation, the accuracy of type 1 and 2 were 0.281, 0.7323 respectively; and the F1 score were 0.1768, 0.6583 respectively. For the WRN model, while the type 1 grouping achieved an accuracy of 0.1041 and F1 score of 0.0599, the type 2 achieved an accuracy of 0.3182 and F1 score of 0.2071. Incorporating ± 3years of deviation, the accuracy of type 1 and 2 were 0.2716, 0.7323 respectively; and the F1 score were 0.1709, 0.6437 respectively.

CONCLUSIONS

The application of entire panorama image data for supervised with classification by heuristics grouping with ± 3years of deviation for supervised learning models and demonstrated satisfactory outcome for the age estimation.

Dataset generated in a systematic review and meta-analysis of biological clocks as age estimation markers in animal ecology

The dataset comprises a comprehensive systematic review and meta-analysis exploring the utility of biological clocks as age estimation markers in the context of animal ecology. The systematic review adhered to PRISMA guidelines and employed optimized Boolean search strings to retrieve relevant studies from Scopus and Dimensions databases. A total of 78 methylation studies and 108 telomere studies were included after rigorous screening. Effect sizes were computed, and statistical transformations were applied when necessary, ensuring compatibility for meta-analysis. Data from these studies were meticulously collected, encompassing statistical measures, study attributes, and additional biological information. The dataset comprises several folders, carefully organized to facilitate access and understanding. It contains raw and processed data used in the systematic review and meta-analysis, including Boolean search strings, database search results, citation network analysis data, PRISMA statements, extracted study data, and input data for meta-analysis. Each folder's contents are described in detail, ensuring clarity and reusability. This dataset aggregates primary research studies spanning diverse ecosystems and taxa, providing a valuable resource for researchers, biodiversity managers and policymakers. This dataset offers a wealth of information and analysis potential for researchers studying age estimation markers in animal ecology, serving as a robust foundation for future investigations and reviews in this evolving field.

DENTAL AGE ESTIMATION USING THE RADIOGRAPHIC VISIBILITY OF PERIODONTAL LIGAMENT AROUND LOWER THIRD MOLARS AMONG SELECTED NIGERIANS

Background

Age estimation for sporting activities, legal age determination and migration purpose is oftentimes essential, which makes the need for a scientifically proven method of age estimation an important aspect of medical practice. Forensic odontology is an essential aspect of forensic practice and may be a veritable tool in age estimation.

Aim and Objective

The objective of this study was to evaluate the usefulness of orthopantomograms (OPG) in age estimation among selected Nigerians.

Methodology

A retrospective assessment of 202 OPGs was done to review the visibility of the periodontal ligament of third molars with completed root formation according to the methods described by Olze et al (2010). Individual ages were then calculated by deducting date of exposure from the date of birth recorded in years. Mean age with standard deviation were calculated for each group.

Results

Assessing the minimum and maximum age at which each of the stages of the radiographic visibility of the periodontal ligament as seen on the OPGs revealed that there was a gradual increase in the age at which the stage increment occurred, with a few exceptions. Comparison of the radiographic visibility of the periodontal ligament revealed that males tend to achieve early periodontal visibility stages compared to females, but the reverse was observed in later stages. Age 17 is more than likely attained in any person found within stages 1 to 3 as the minimum age found in these stages were above 17 years.

Conclusion

With a few exceptions, the assessment of periodontal ligament visibility on OPGs can adequately predict the age of individuals. Thus, the use of this method may need to be combined with other methods in accurate determination of dental age in instances of forensic age estimation.

Using machine learning to determine age over 16 based on development of third molar and periodontal ligament of second molar

BACKGROUND

Having a reliable and feasible method to estimate whether an individual has reached 16 years of age would greatly benefit forensic analysis. The study of age using dental information has matured recently. In addition, machine learning (ML) is gradually being applied for dental age estimation.

AIM

The purpose of this study was to evaluate the development of the third molar using the Demirjian method (Demirjian3M), measure the development index of the third molar (I3M) using the method by Cameriere, and assess the periodontal ligament development of the second molar (PL2M). This study aimed to predict whether Chinese adolescents have reached the age of criminal responsibility (16 years) by combining the above measurements with ML techniques.

SUBJECTS & METHODS

A total of 665 Chinese adolescents aged between 12 and 20 years were recruited for this study. The development of the second and third molars was evaluated by taking orthopantomographs. ML algorithms, including random forests (RF), decision trees (DT), support vector machines (SVM), K-nearest neighbours (KNN), Bernoulli Naive Bayes (BNB), and logistic regression (LR), were used for training and testing to determine the dental age. This is the first study to combine ML with an evaluation of periodontal ligament and tooth development to predict whether individuals are over 16 years of age.

RESULTS AND CONCLUSIONS

The study showed that SVM had the highest Bayesian posterior probability at 0.917 and a Youden index of 0.752. This finding provides an important reference for forensic identification, and the combination of traditional methods and ML is expected to improve the accuracy of age determination for this population, which is of substantial significance for criminal litigation.

Differences in body wall metabolites of Apostichopus japonicus of different ages in liquid chromatography-tandem mass spectrometry

Apostichopus japonicus is a marine invertebrate with high economic value. Analysis of the effects of age on the structure of this species is important for understanding the status of the population and conservation. In this study, metabolite analysis of the body walls of A. japonicus of three different ages (1, 2, and 3 years) was performed using LC-MS/MS. Metabolite analysis was performed for the KEGG metabolic pathway. The partial least squares-discriminant analysis is clearly distinguished metabolites in the three groups of A. japonicus. A total of 59, 222, and 179 different metabolites were detected in the age 3 vs age 2, age 3 vs age 1, and age 2 vs age 1 controls, respectively (P < 0.05). These metabolic differences involved several metabolic pathways, including phenylalanine metabolism, taurine and hypotaurine metabolism, sulfur metabolism et al. Thiamin, riboflavin, lipoic acid, acetyl l-carnitine levels increase with age, trans-10-heptadecenoic acid, stearic acid, pentadecanoic acid, dibutyl sebacate, and 8,15-diHETE levels decrease with age, which these metabolites can be used as potential markers to determine the age of A. japonicus. Our results provide the foundation for determining the age of A. japonicus and are important for the conservation of germplasm resources of A. japonicus.

Age determination through DNA methylation patterns in fingernails and toenails

Over the past decade, age prediction based on DNA methylation has become a vastly investigated topic; many age prediction models have been developed based on different DNAm markers and using various tissues. However, the potential of using nails to this end has not yet been explored. Their inherent resistance to decay and ease of sampling would offer an advantage in cases where post-mortem degradation poses challenges concerning sample collection and DNA-extraction. In the current study, clippings from both fingernails and toenails were collected from 108 living test subjects (age range: 0-96 years). The methylation status of 15 CpGs located in 4 previously established age-related markers (ASPA, EDARADD, PDE4C, ELOVL2) was investigated through pyrosequencing of bisulphite converted DNA. Significant dissimilarities in methylation levels were observed between all four limbs, hence both limb-specific age prediction models and prediction models combining multiple sampling locations were developed. When applied to their respective test sets, these models yielded a mean absolute deviation between predicted and chronological age ranging from 5.48 to 9.36 years when using ordinary least squares regression. In addition, the assay was tested on methylation data derived from 5 nail samples collected from deceased individuals, demonstrating its feasibility for application in post-mortem cases. In conclusion, this study provides the first proof that chronological age can be assessed through DNA methylation patterns in nails.

New specimens of the early Permian apex predator Varanops brevirostris at Richards Spur, Oklahoma, with histological information about its growth pattern

An articulated pelvic region and additional isolated material of Varanops brevirostris, which are indistinguishable from those of the generotype from the Cacops bonebed, demonstrate the presence of this large varanopid at the Richards Spur locality. The articulated specimen includes lumbar, sacral, and anterior caudal vertebrae, partial pelvis, femur, and proximal part of tibia, confirming the autapomorphies previously suggested for this species. These include the presence of distinct blade-like shapes of the neural spines in the sacral region, the presence of deeply excavated pubis, and the presence of a distinct transverse ridge on the ventral surface of the femur distal to the intertrochanteric fossa. It has also been found that the transverse ridges and grooves become larger during ontogeny since the juvenile specimen did not exhibit a well-developed ridge. Histological analysis of isolated limb bones and neutron computed tomography (nCT) of the articulated specimen indicate that the latter likely belonged to an adult individual. This is in contrast to the other varanopid at Richards Spur, the significantly smaller, more gracile predator Mesenosaurus efremovi, which also shows the presence of growth lines and the external fundamental system with an estimated minimum age of fourteen.

Applicability of the London Atlas method in the East China population

BACKGROUND

Dental age estimation is important for developmental assessment and individual identification. The London Atlas, a recently proposed method for dental age estimation, has been reported to perform satisfactorily in various populations.

OBJECTIVE

In this study, we assessed the reproducibility, repeatability and applicability of the London Atlas method in the East China population and compared it with the Demirjian method.

MATERIALS AND METHODS

We assessed panoramic radiographs of 835 pediatric patients ages 6.0-19.9 years using the London Atlas and the Demirjian method. We employed the intraclass correlation coefficient and Bland-Altman analysis to evaluate reproducibility and repeatability, respectively. We assessed the agreement between dental age and chronological age and calculated 95% and 80% prediction intervals for each dental age stage. Sensitivity, specificity and predictive values were calculated to assess the performance of both methods for identifying threshold ages.

RESULTS

The London Atlas has better reproducibility and repeatability (intraclass correlation coefficients: 0.98 and 0.99; 95% limits of agreement: - 1.34 to 1.56 and - 1.22 to 0.88, respectively). Dental age estimated using the London Atlas was closer to chronological age in both genders (median absolute error = 0.58). The 95% prediction intervals for chronological age were wide (0.99 to 9.89 years).

CONCLUSION

The London Atlas has excellent reproducibility and repeatability. Thus, it might offer an alternative method for developmental assessment. We observed considerable variation in dental development in the East China population, which needs further research.

Age Determination in Children Using Camirere's Indian Specific Formula: A Radiographic Study Using Orthopantomographs

AIM

Determination of age is a pivotal part of forensic dentistry. Since many dental age determination methods are invasive, Cameriere introduced a radiographic method where age evaluation was carried out using an orthopantomogram (OPG). An adaptation of the same formula was later formulated by Rai et al. for the Indian population. The aim of the study was to assess the age and to dictate the efficiency of the Indian version of Cameriere's formula in the Chennai subpopulation.

MATERIALS AND METHODS

This study consisted of radiographs belonging to 50 individuals with an age range of 5-15 years. Radiographs were taken using the OPG and the soft copies obtained were analyzed. The variables such as seven left and right permanent mandibular teeth and the number of teeth with closed apical, and with open apical, ends of roots were examined and measured. The obtained data, after substituting in the formula was statistically analyzed using paired and unpaired t-test and Pearson's correlation coefficient test.

RESULTS

On comparing dental age and chronological age, statistically significant results were obtained on both sides of the radiograph. Between genders, both sides of the radiograph showed non-significant results. On correlating the sides, the left side showed greater accuracy in age determination compared to the right side of the OPG.

CONCLUSION

Age estimation using Indian-specified formula provides a near good estimate and hence can be a reliable method to measure the chronological age of the participants.

CLINICAL SIGNIFICANCE

The Indian version of the Cameriere's formula can be used as a rational tool to assess the age of young children and adolescents.

Response of the Christchurch groundwater system to exploitation: Carbon-14 and tritium study revisited

The Christchurch groundwater system is an exceptional water resource with very high drinking water quality supplying all the water requirements of the city. The groundwater system has changed over the years because of rising groundwater abstraction due to increasing population and development. The present (2017) data revealed slightly older ¹⁴C ages and increasingly steep west-east age gradients compared to the earlier work from 1976 to 2006, showing continued upflow of deep water into the exploited aquifers which is much older on the east (coastal) side than on the west (inland) side. In addition, the ³H ages for wells on the west side of the system are often much younger than their ¹⁴C ages showing that there is input of young shallow water to the wells in addition to the deep water input. Application of a binary model identifies the ages and amounts of the two components, showing that the young component is becoming younger although smaller as a proportion of the flow, and the old component from depth is becoming larger. Newly completed wells near the Waimakariri River have allowed identification of the young component, which is almost entirely composed of very young Waimakariri River seepage at all depths and therefore has very little chemical loading. Instead any chemical input (e.g. chloride, nitrate) to the Christchurch aquifers is being brought in by the old deep component which on the western side of the Christchurch system is derived from rainfall recharge on the developing Ashley-Waimakariri Plains area (plus river seepage). Chemical traces of this deep input from the northwest are at present very subtle, although more appreciable signals are seen in some wells further to the north of Christchurch. In the future, slowly increasing chemical input to the Christchurch aquifers on the west side of the system is to be expected as abstraction increases.

A quick method of determining the age of 8 years old: Based on the first premolars on Eastern Chinese population

BACKGROUND

Whether an individual is over 8 years old is of great significance in clinical medicine and law. The Demirjian, Willems and Cameriere methods are one of the most widely used methods of dental age estimation, but neither method was suitable in Eastern China. And all of them are time-consuming for clinical work. A new and time-saving method for judging whether an individual is 8 years old is yet to be proposed on Eastern Chinese population.

AIM

The paper proposes a method for judging whether an individual is 8 years old based on the relationship between age and the first premolar maturity index (I_1PM), which is related to the measurement of the open apices of the first premolar.

SUBJECTS & METHODS

It is a retrospective study where orthopantomograms of 748 children (356 female and 392male) aged 5-13 years were collected and analyzed. Linear regression was used to infer the value of I_1PM for eastern China. Furthermore, this method was compared to those based on Demirjian's stages F.

RESULTS AND CONCLUSIONS

A cutoff value of I_1PM = 0.35 was taken. The sensitivity of this test was 90.0% and specificity was 93.3%. Furthermore, the proportion of individuals with a correct classification was 90.9%. The results of the test showed that Demirjian's stage F performance was lightly better than I_1pm < 0.35. However, the sensitivity, specificity, and overall accuracy of both are greater than or equal to 90.0%, and the differences are not very significant.

Age determination of the adult blow fly Lucilia sericata (Diptera: Calliphoridae) through quantitative pteridine fluorescence analysis

Determination of a minimal postmortem interval via age estimation of necrophagous diptera has been restricted to the juvenile stages and the time until emergence of the adult fly, i.e. up until 2-6 weeks depending on species and temperature. Age estimation of adult flies could extend this period by adding the age of the fly to the time needed for complete development. In this context pteridines are promising metabolites, as they accumulate in the eyes of flies with increasing age. We studied adults of the blow fly Lucilia sericata at constant temperatures of 16 °C and 25 °C up to an age of 25 days and estimated their pteridine levels by fluorescence spectroscopy. Age was given in accumulated degree days (ADD) across temperatures. Additionally, a mock case was set up to test the applicability of the method. Pteridine increases logarithmically with increasing ADD, but after 70-80 ADD the increase slows down and the curve approaches a maximum. Sex had a significant impact (p < 4.09 × 10-6) on pteridine fluorescence level, while body-size and head-width did not. The mock case demonstrated that a slight overestimation of the real age (in ADD) only occurred in two out of 30 samples. Age determination of L. sericata on the basis of pteridine levels seems to be limited to an age of about 70 ADD, but depending on the ambient temperature this could cover an extra amount of time of about 5-7 days after completion of the metamorphosis.

Age determination in dog puppies by teeth examination: legal, health and welfare implications, review of the literature and practical considerations

Age determination of puppies represents a significant issue of animal welfare and forensic medicine, particularly for what concerns trade and imports of dogs. Despite the movement of puppy dogs before the age of 15 weeks is forbidden by Regulation (EU) No 576/2013, the occurrence of illegal transport of younger puppies is not uncommon. The illegal trade of puppies increases instances of falsified documentation, the counterfeit of vaccine certificates and discrepancies between the declared age and the real age of the puppies. Consequently, determining the exact age of animals and evaluating their welfare become legally crucial. Dental examination currently represents the most common approach to estimate the age of a puppy in clinical practice and in forensic investigations. In this work we addressed the legal, health and welfare issues associated with dogs' trade and import and we reviewed the existing literature referring to the assessment of age in dogs by dental examination. The imprecision and inaccuracy of this method make it poorly convincing in legal proceedings. The reasons for such vagueness are to be ascribed both to the lack of standardization and to many variability factors (size, breed, sex, diet, etc.) which influence dental eruption and development.

Age-dependent differences in iris colouration of passerines during autumn migration in Central Europe

Avian eye colour changes with age, but many aspects of this transition are still insufficiently understood. We examined if an individual’s sex, age, species and body condition are related to the iris colour in common migratory passerines during their autumn passage through Central Europe. A total of 1,399 individuals from nine numerous species were ringed and examined in late autumn in northern Poland. Each individual was sexed by plumage (if possible) and assigned to one of three classes of the iris colour—typical for immatures, typical for adults and intermediate. We found that the iris was typical in 97.7% cases of immatures and in 75.8% cases of adults and this difference was significant. Species, sex and body mass index (BMI) had no significant influence on the iris colour. We show that iris colour in passerines in late autumn is strongly age-dependent and thus can serve as a reliable feature for ageing in field studies, especially in species difficult to age by plumage.

Determination of epigenetic age through DNA methylation of NPTX2 gene using buccal scrapes: A pilot study

Context

DNA methylation (DNAm) age can be used to evaluate the chronological age of individuals often called "epigenetic age." In this study, buccal scrape samples were used for the determination of epigenetic age.

Aims

To examine if epigenetic age could be determined using neuronal pentraxin 2 (NPTX2) gene in buccal cells.

Setting and Design

This cohort study was designed to validate the use of buccal cells for epigenetic age estimation. Sanger sequencing was used to determine the genetic sequence of the gene of interest postamplification. Nucleotide base sequence for NPTX2 gene was obtained for each case using this protocol.

Subjects and Methods

The study was conducted on buccal scrapes obtained from 26 subjects of both genders, whose age varied from 1 to 65 years. The samples, collected by wooden spatulas, were placed in cell suspension buffer and stored at 4°C until transported to the laboratory.

Results

Methylation levels of 5'-C-phosphate-G-3' located in the gene NPTX2 of 26 subjects were studied and analyzed by bisulfate sequencing. The percentage of methylation in this study falls in the range between 15% and 51%.

Conclusion

In this study, a sufficient amount of gDNA was retrieved from the buccal cells, thus confirming that buccal scrape was a feasible technique to obtain ample DNA. This study also showed that DNAm-polymerase chain reaction method was a feasible method for the evaluation of methylation pattern of NPTX2 gene.

Lipofuscin Level in Eyestalk Blue Swimming Crab, Portunus pelagicus at Different Sexes

BACKGROUND AND OBJECTIVE

The accumulation of lipofuscin (LF) is an alternative technique to identify age of crustacean species. However, the exact sites and the level of the LF concentration were unknown especially for different sexes of blue swimming crab, Portunus pelagicus. Thus, the present study was aimed to identify which part of the eyestalk of P. pelagicus contains more LF levels in order to establish a specific target part of samples.

MATERIALS AND METHODS

Thus, crab samples for this study were sampled from the wild habitat at Setiu wetlands, Terengganu, Malaysia. A total of 100 samples of with the same size (80±5 mm carapace width) were sampled and the eyestalk dissected for LF extraction. The determination of LF sites and levels in the eyestalks organ was taken from the area between the distal tangential layer (DTL) and proximal tangential layer (PTL). The lower part of the eyestalk was taken from the PTL until the end of the eyestalk.

RESULTS

The upper part of the crab's eyestalk was higher in the males crabs compared to the females crabs. LF index also shown that the upper part of crab's eyestalk have higher concentration compared to the lower part.

CONCLUSION

The left crab's eyestalk had the higher LF index especially in males compared to females but the total concentration was higher in female crabs. Knowing which part has highly dense accumulation of LF helps in LF detection of the tissue and further helps for age determination for this species.

Validation of Age Determination with Historical Events in Birnin Kebbi, Northwest Nigeria

Context:

Birth registration is not universal and remains elusive for some people living in developing countries, such as Nigeria; hence, age determination for healthcare and health-related research is often problematic.

Aims:

The aim is to validate the use of a historical events' scale as a tool for estimating the age of Nigerian adults residing in Birnin Kebbi, Northwest Nigeria.

Settings and Design:

A cross-sectional survey was conducted in Birnin Kebbi, a metropolitan capital city of Kebbi state, Northwest Nigeria, and included adults aged 18 years and older with a valid document indicating their year of birth.

Subjects and Methods:

Seven historical events comprising major national events were cross-referenced to the individual's personal history to estimate their ages, which were then compared to their documented ages.

Statistical Analysis Used:

Relationship of the documented and estimated ages was assessed with the Spearman's rank-order correlation and intraclass correlation coefficient (ICC) analyses.

Results:

A total of 288 subjects (63.2% males) with a mean documented age of 34.5 ± 11.3 (range 18–75) years were surveyed. The mean estimated age was 32.5 ± 11.18 years. Spearman's rank-order correlation analysis showed a statistically strong positive correlation between the actual and estimated ages (0.953, P < 0.001). The ICC between documented and estimated ages was 0.968 (95% confidence interval = 0.959–0.975).

Conclusions:

The use of this tool in Nigerian adults provides a reasonably accurate age estimation. Its use in populations and communities with inadequate birth registration may improve the quality of age-related health data in Nigerian adults.

Dataset on body weight, carapace width increment and growth band count of mud crabs, Scylla olivacea

The present paper contains two datasets; i) the growth band count (GBC) of mud crab, Scylla olivacea collected from Setiu Wetlands, Terengganu coastal water, East coast of Peninsular Malaysia and ii) the increment sizes of body weight (BW) and carapace width (CW) of immature S. olivace after molting. The datasets presented here were associated with the research articles entitled i) “Study on carapace width growth band counts relationship of orange mud crab, S. olivacea (Herbst, 1796) from Terengganu Coastal Waters, Malaysia” (Hasyima-Ismail et al. 2017) [1] and ii) “Relationship between the carapace width and body weight increments and the confirmation of Stage 1 ovary after the molting of immature orange mud crabs, S. olivacea (Herbst, 1796), in captivity” (Amin-Safwan et al. 2019-2020) [2], and provided here as raw data of Supplementary materials. Raw datasets for GBC in the wild were generated by examination of the thin cross sectioning process of the gastric mill of S. olivacea. The GBC were measured for each individual crab wherein band counts ranged from 1 to 3. The analysis provides evidence that the GBC of the crabs can be determined through both mesocardiac and zygocardiac ossicles. This data is of importance to researchers for estimation of stock assessment and improvement of fisheries management to further improve policy. For the BW-CW increment data, a total of 135 immature crabs were sampled from Setiu Wetlands, Terengganu, Malaysia, and were introduced to limb autotomy technique in order to induced molt. Crabs were reared until successful molting and immediately prior to hardened shell, before final measurement of body weight and carapace width determination. Recorded data was analyzed by calculating the increment sizes, along with correlation and regression analysis between body weight and carapace width of mud crabs.

Age-dependent changes in cuticular color and pteridine levels in a clonal ant

Social insects are emerging models for studying aging and the longevity/fecundity trade-off. Research on the demography of colonies and populations are hampered by the lack of reliable age markers. Here we investigate the suitability of cuticular pigmentation and pteridine fluorescence for age grading individuals of the clonal ant Platythyrea punctata. We found that both traits varied with age. Cuticular color darkened with individual's age until 25-30 days after hatching. For pteridine fluorescence, we found that P. punctata workers show a decrease in head pteridine levels over time until 70-80 days of age. Together with other markers, such as age-based behavior, cuticular coloration and pteridine fluorescence may help to estimate the age structure of colonies.

Dental age estimation in Somali children and sub-adults combining permanent teeth and third molar development

Estimation of an individual’s age has important applications in forensics. In young individuals, it often relies on separate evaluations of permanent teeth (PT) and third molars (TM) development. Here, we analysed the age prediction performance of combined information from PT and TM in an unusual sample of healthy Somalis, born and living in Finland. PT development was staged according to Demirjian et al. (Hum Biol, 1973) and TM development according to Köhler et al. (Ann Anat, 1994), using panoramic radiographs from 803 subjects (397 males, 406 females) aged 3–23 years. A sex-specific Bayesian age-estimation model for the multivariate distribution of the stages conditional on age was fitted on PT, TM and PT and TM combined. The age-estimation performances were validated and quantified. The approach combining PT and TM only overestimated age with an ME of − 0.031 years in males and − 0.011 years in females, indicating the best age prediction performance.

Ascertaining of age by Raman spectroscopic analysis of apical dentin - A forensic study

Context:

Age estimation in forensics employ various methods of which Raman microspectroscopy provides a noninvasive method by assessing various parts of dentin.

Aim and Objectives:

The aim of this study is to ascertain the age of carious tooth using Raman spectra of apical dentin and to correlate the similarity of the spectra in a defined age group.

Settings and Design:

Teeth of known age from Indian population (n=48) and morphology (incisors, canine, premolars, molars) indicated for extraction due to caries were allocated into four groups, i.e., Group A (21-30 years), Group B (31-40 years), Group C (41-50 years) and Group D (51-60 years).

Materials and Methods:

Teeth were sectioned and the apical 2 mm of dentin was examined by a Raman microspectroscopy machine for spectra from 400 cm⁻¹ to 1500 cm⁻¹, and peak at phosphate group at 963 cm⁻¹ was taken for statistical analysis.

Statistical Analysis Used:

The data were analyzed using IBM SPSS version 20.0.

Results:

Pearson's correlation to test the strength of linear relation of the spectra of the teeth within an age group showed an “r” value approaching 1. One-way ANOVA to test the difference between means of spectrum values obtained between the four age groups was statistically significant at P < 0.05.

Conclusion:

Raman spectroscopic analysis of apical dentin of teeth affected by caries can also be used to estimate the age and the Raman spectra obtained differed for different age groups, and the same can be advocated as an alternative method to ascertain age in forensic dentistry.

Measurement of the 231Pa/235U ratio for the age determination of uranium materials

The paper describes the age (production date) determination of uranium reference materials using the ²³¹Pa/²³⁵U ratio. Direct addition of ²³⁷Np in secular equilibrium with its ²³³Pa daughter was chosen instead of the regular milking of ²³⁷Np to avoid possible loss of Pa. Sample preparation consists of a fast, one-step procedure. The developed method using ICP-MS for the measurement of ²³¹Pa is more precise than alpha spectrometry and is applicable for freshly produced low-enriched uranium materials. The measured ages are in good agreement with the reported production dates, thus the ²³¹Pa/²³⁵U chronometer can be applied for validation of ²³⁰Th/²³⁴U in nuclear forensics and safeguards.

Effect of Cd and Pb Pollutions on Physiological Growth: Wavelet Neural Network (WNN) as a New Approach on Age Determination of Coenobita scaevola

Environmental pollution of aquatic ecosystems leads to an interference in several fundamental biochemical and physiological functions. In this study the interference of Cd and Pb pollutions on the physiological growth and subsequently on the age determination was investigated. The hermit crab, Coenobita scaevola (C.s) was selected as a bioaccumulator in this study. The direct and indirect age determination methods were carried out using annual band counts and carapace length, respectively. The results showed that, there was very low correlation (R² < 0.5) between direct and indirect age determination. Wavelet Neural Network (WNN) was applied to take into account the environmental effects such as the accumulation of Cd and Pb elements in the C.s' tissues. It was observed that WNN successfully enhanced the growth rate model and estimated the C.s' age (R² > 0.95). In addition, it was concluded that the environmental pollution had interaction with the growth physiology such as weight and length.

The crustacean cuticle does not record chronological age: New evidence from the gastric mill ossicles

A proposed method to determine chronological age of crustaceans uses putative annual bands in the gastric mill ossicles of the foregut. The interpretation of cuticle bands as growth rings is based on the idea that ossicles are retained through the moult and could accumulate a continuous record of age. However, recent studies presented conflicting findings on the dynamics of gastric mill ossicles during ecdysis. We herein study cuticle bands in ossicles in four species of commercially important decapod crustaceans (Homarus gammarus, Nephrops norvegicus, Cancer pagurus and Necora puber) in different phases of the moult cycle using dissections, light microscopy, micro-computed tomography and cryo-scanning electron microscopy. Our results demonstrate that the gastric mill is moulted and ossicles are not retained but replaced during ecdysis. It is therefore not plausible to conclude that ossicles register a lifetime growth record as annual bands and thereby provide age information. Other mechanisms for the formation of cuticle bands and their correlation to size-based age estimates need to be considered and the effect of moulting on other cuticle structures where 'annual growth bands' have been reported should be investigated urgently. Based on our results, there is no evidence for a causative link between cuticle bands and chronological age, meaning it is unreliable for determining crustacean age.

Proof of concept study of age-dependent DNA methylation markers across different tissues by massive parallel sequencing

The use of DNA methylation (DNAm) for chronological age determination has been widely investigated within the last few years for its application within the field of forensic genetics. The majority of forensic studies are based on blood, saliva, and buccal cell samples, respectively. Although these types of samples represent an extensive amount of traces found at a crime scene or are readily available from individuals, samples from other tissues can be relevant for forensic investigations. Age determination could be important for cases involving unidentifiable bodies and based on remaining soft tissue e.g. brain and muscle, or completely depend on hard tissue such as bone. However, due to the cell type specificity of DNAm, it is not evident whether cell type specific age-dependent CpG positions are also applicable for age determination in other cell types. Within this pilot study, we investigated whether 13 previously selected age-dependent loci based on whole blood analysis including amongst others ELOVL2, TRIM59, F5, and KLF14 also have predictive value in other forensically relevant tissues. Samples of brain, bone, muscle, buccal swabs, and whole blood of 29 deceased individuals (age range 0-87 years) were analyzed for these 13 age-dependent markers using massive parallel sequencing. Seven of these loci did show age-dependency in all five tissues. The change of DNAm during lifetime was different in the set of tissues analyzed, and sometimes other CpG sites within the loci showed a higher age-dependency. This pilot study shows the potential of existing blood DNAm markers for age-determination to analyze other tissues than blood. We identified seven known blood-based DNAm markers for use in muscle, brain, bone, buccal swabs, and blood. Nevertheless, a different reference set for each tissue is needed to adapt for tissue-specific changes of the DNAm over time.

Age determination by spheno-occipital synchondrosis fusion in Central Indian population

The spheno occipital suture synchondrosis is a vital contributor to adolescent and adult age estimation in that it can provide an upper or lower age bound depending on its state of fusion. The present study evaluates the utility of the spheno-occipital suture fusion in age estimation of the Central Indian population. The sample includes 198 (117 males and 81 females) cadavers aged between 8 to 26 years. Grading was done using Mitra-Akhlaghi Scale as - Open, Semi closed and Closed. Our study demonstrates that a significant linear correlation exists between the age of an individual and spheno-occipital suture closure for both the sexes and observation of the degree of fusion of this single suture allows the prediction of age in mature individuals.

Age and Growth of Elasmobranchs and Applications to Fisheries Management and Conservation in the Northeast Pacific Ocean

In addition to being an academic endeavour, the practical purpose of conducting age and growth studies on fishes is to provide biological data to stock assessment scientists and fisheries managers so they may better understand population demographics and manage exploitation rates. Age and size data are used to build growth models, which are a critical component of stock assessments. Though age determination of elasmobranchs in the northeast Pacific Ocean (NEP) began in the 1930s, the field has evolved substantially in recent years, allowing scientists to incorporate age data into assessments for more species than ever before. Owing to the highly diverse biology of this group of fishes, each species has its own set of challenges with regard to age determination. Age determination methods typically rely on semicalcified hard structures that form regular growth patterns; however, the structure selected and preparation method used is often species specific. New staining techniques have improved the ability to assess age and improve ageing precision for some species, and advances in microchemical methods have allowed for independent means of estimating age and validating age determination accuracy. Here we describe current age determination methods for NEP elasmobranchs. While the library of available techniques is increasing, there are still some NEP species for which reliable ageing methods have yet to be defined; we discuss these challenges and potential avenues of future research. Finally, we conclude by describing how age estimates are used in growth models and subsequently in stock assessments of selected NEP elasmobranchs.

Relationships between age and microarchitectural descriptors of iliac trabecular bone determined by microCT

AIM

Estimation of age at death is a major issue in anthropology. The main anthropological histological methods propose studying the architecture of cortical bone. In bone histomorphometry, researches on metabolic bone diseases have provided normative tables for trabecular bone volume (BV/TV) according to age and gender of individuals on trans-iliac bone biopsies. We have used microCT, a non-destructive tool for measuring bone volume and trabecular descriptors to compare the French tables to a series of forensic anthropological population and if the two iliac bones could be used interchangeably.

METHODOLOGY

Coxal bone of a personal forensic collection whose age and gender were known (DNA identification) were used. Bone samples, centered on the same area than bone biopsy. MicroCT (pixel size: 36μm) was used to measure BV/TV and morphometric trabecular parameters of microarchitecture. An adjusted Z-score was calculated for BV/TV to compare with normative tables and a right/left comparison of trabecular parameters was provided.

RESULTS

Twenty-seven iliac bones, which 20 forming 10 complete pelvises, aged between 24 and 73y.o. (average of 47.7 y.o.) were used. All adjusted Z-score were within normal values. There was a strong positive correlation between right and left sides for Tb.Th, Tb.N and Tb.Sp, but an insignificant correlation was obtained for BV/TV.

CONCLUSION

Normative tables between age and BV/TV are valid and therefore usable in anthropology. They may represent an alternative to determine the age at death. Nevertheless, it requires a precise technique that could be a drawback in current practice.

Variations In The Age Of Fusion Of Ischial Tuberosity; A Radiological Study

BACKGROUND

Human skeleton develops from separate ossification centres which continue to ossify till the bone is completely formed. Radiological techniques are very reliable and useful method for estimating the age of individual for forensic and criminal reasons by observing these ossification centres. External inspection for age determination is liable to error. This study is thus aimed to assess the variation in age of fusion of ischial tuberosity in Pakistani population.

METHODS

It was a cross sectional study, wherein data was retrospectively collected at Bahawalpur Victoria Hospital, a tertiary referral centre in which consecutively selected 47 females and 121 males between 10-24 years of age, attending the outpatient, referred from National Database and Registration Authority for the confirmation of age were selected.

RESULTS

There were a total of 13 cases in stage I, 98 in stage II, 23 in stage III and 34 in stage IV. In stage II maximum numbers of cases were between the ages of 19-22 years whereas in stage IV the maximum numbers of cases were between 21-24 years of age.

CONCLUSIONS

It is concluded that the earliest appearance of epiphyseal centre in males occurred at 12-13 years and in females at 10-11 years. While earliest complete union was seen at the age of 19-20 years in females and 16-17 years in males. All cases in age group of 23-24 years showed complete union.

Validation of reference materials for uranium radiochronometry in the frame of nuclear forensic investigations

The results of a joint effort by expert nuclear forensic laboratories in the area of age dating of uranium, i.e. the elapsed time since the last chemical purification of the material are presented and discussed. Completely separated uranium materials of known production date were distributed among the laboratories, and the samples were dated according to routine laboratory procedures by the measurement of the (230)Th/(234)U ratio. The measurement results were in good agreement with the known production date showing that the concept for preparing uranium age dating reference material based on complete separation is valid. Detailed knowledge of the laboratory procedures used for uranium age dating allows the identification of possible improvements in the current protocols and the development of improved practice in the future. The availability of age dating reference materials as well as the evolvement of the age dating best-practice protocol will increase the relevance and applicability of age dating as part of the tool-kit available for nuclear forensic investigations.

De novo transcriptome analysis and highly sensitive digital gene expression profiling of Calliphora vicina (Diptera: Calliphoridae) pupae using MACE (Massive Analysis of cDNA Ends)

Determining a post-mortem interval using the weight or length of blow fly larvae to calculate the insect's age is well established. However, to date, there are only a handful studies dealing with age estimation of blow fly pupae, in which weight or length cannot be used as a relevant parameter. The analysis of genetic markers, which indicate a certain developmental stage, can extend the period for a successful post-mortem interval determination. In order to break new ground in the field of age determination of forensic relevant blow flies, we performed a de novo transcriptome analysis of Calliphora vicina pupae at 15 different developmental stages. Obtained data serve as base to establish molecular age determination techniques. We used a new, deeper, and more cost-effective digital gene expression profiling method called MACE (Massive Analysis of cDNA Ends). We generated 15 libraries out of 15 developmental stages, with 3-8 million reads per library. In total, 53,539 distinct transcripts were detected, and 7548 were annotated to known insect genes. The analysis provides high-resolution gene expression profiles of all covered transcripts, which were used to identify differentially expressed genetic markers as candidates for a molecular age estimation of C. vicina pupae. Moreover, the analysis allows insights into gene activity of pupal development and the relationship between different genes interesting for insect development in general.

A model study into the effects of light and temperature on the degradation of fingerprint constituents

Determining the order of events in a criminal investigation can be crucial in many ways. Although the use of fingermarks is one of the most important forensic tools as a modality of individualisation, placing them in time is a long lasting difficulty. In the study presented in this paper we describe the effects of light and the temperature on depositions of standard solutions containing squalene and cholesterol on paper. The results obtained give a clear view on what type of processes take place during a temperature and a light influenced degradation of the two materials in this study. Using well known methods for the determination of reaction constants it was determined that the degradation mechanism of cholesterol is following a radical route, where the decay of squalene is more affected by temperature.

Age estimation from physiological changes of teeth: A reliable age marker?

Background:

Age is an essential factor in establishing the identity of a person. Teeth are one of the most durable and resilient part of skeleton. Gustafson (1950) suggested the use of six retrogressive dental changes that are seen with increasing age.

Aim:

The aim of the study was to evaluate the results and to check the reliability of modified Gustafson's method for determining the age of an individual.

Materials and Methods:

Total 70 patients in the age group of 20-65 years, undergoing extraction were included in this present work. The ground sections of extracted teeth were prepared and examined under the microscope. Modified Gustafson's criteria were used for the estimation of age. Degree of attrition, root translucency, secondary dentin deposition, cementum apposition, and root resorption were measured. A linear regression formula was obtained using different statistical equations in a sample of 70 patients.

Results:

The mean age difference of total 70 cases studied was ±2.64 years. Difference of actual and calculated age was significant and was observed at 5% level of significance, that is, t-cal > t-tab (t-cal = 7.72). P < 0.05, indicates that the results were statistically significant.

Conclusion:

The present study concludes that Gustafson's method is a reliable method for age estimation with some proposed modifications.

Age determination of subdural hematomas with CT and MRI: a systematic review

OBJECTIVES

To systematically review the literature on dating subdural hematomas (SDHs) on CT and MRI scans.

METHODS

We performed a systematic review in MEDLINE, EMBASE and Cochrane to search for articles that described the appearance of SDHs on CT or MRI in relation to time between trauma and scanning. Two researchers independently screened the articles, assessed methodological quality and performed data extraction. Medians with interquartile ranges were calculated. Differences were tested with a Mann-Whitney U or Kruskal-Wallis H test.

RESULTS

We included 22 studies describing 973 SDHs on CT and 4 studies describing 83 SDHs on MRI. Data from 17 studies (413 SDHs) could be pooled. There were significant differences between time intervals for the different densities on CT (p<0.001). Time interval differed significantly between children and adults for iso- and hypodensity (p=0.000) and hyperdensity (p=0.046). Time interval did not differ significantly between abused and non-abused children. On MRI, time intervals for different signal intensities on T1 and T2 did not differ significantly (p=0.108 and p=0.194, respectively).

CONCLUSIONS

Most time intervals of the different appearances of SDHs on CT and MRI are broad and overlapping. Therefore CT or MRI findings cannot be used to accurately date SDHs.