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Developmental Cell Apr 2022During embryonic development, digits gradually emerge in a periodic pattern. Although genetic evidence indicates that digit formation results from a self-organizing...
During embryonic development, digits gradually emerge in a periodic pattern. Although genetic evidence indicates that digit formation results from a self-organizing process, the underlying mechanisms are still unclear. Here, we find that convergent-extension tissue flows driven by active stresses underlie digit formation. These active stresses simultaneously shape cartilage condensations and lead to the emergence of a compressive stress region that promotes high activin/p-SMAD/SOX9 expression, thereby defining digit-organizing centers via a mechanical feedback. In Wnt5a mutants, such mechanical feedback is disrupted due to the loss of active stresses, organizing centers do not emerge, and digit formation is precluded. Thus, digit emergence does not result solely from molecular interactions, as was previously thought, but requires a mechanical feedback that ensures continuous coupling between phalanx specification and elongation. Our work, which links mechanical and molecular signals, provides a mechanistic context for the emergence of organizing centers that may underlie various developmental processes.
Topics: Activins; Chondrogenesis; Extremities; Feedback; Gene Expression Regulation, Developmental; Morphogenesis
PubMed: 35413235
DOI: 10.1016/j.devcel.2022.03.004 -
Scientific Reports May 2021Hands and digits tend to be sexually dimorphic and may reflect prenatal androgen exposure. In the past years, the literature introduced several hand and digit measures,...
Hands and digits tend to be sexually dimorphic and may reflect prenatal androgen exposure. In the past years, the literature introduced several hand and digit measures, but there is a lack of studies in prepubertal cohorts. The available literature reports more heterogeneous findings in prepubertal compared to postpubertal cohorts. The comparability of the available studies is further limited by the study design and different measurement techniques. The present study compared the reliability and sex differences of available hand and digit measures, namely digit lengths of 2D, 3D, 4D, 5D, digit ratios 2D:4D, 2D:5D, 3D:4D, 3D:5D, 4D:5D, relative digit lengths rel2, rel3, rel4, rel5, directional asymmetry of right and left 2D:4D (D), hand width, length, and index of 399 male and 364 female 6-month-old German infants within one study using only indirect and computer-assisted measurements. The inter-examiner reliability was excellent while the test-retest reliability of hand scans was only moderate to high. Boys exhibited longer digits as well as wider and longer hands than girls, but smaller digit ratios, with ratios comprising the fifth digit revealing the largest effect sizes. Other hand and digit ratios revealed sex differences to some extent. The findings promote the assumption of sexual dimorphic hand and digit measures. However, by comparing the results of the available literature, there remains an uncertainty regarding the underlying hypothesis. Specifically in prepubertal cohorts, i.e. before the influence of fluctuating hormones, significant effects should be expected. It seems like other factors than the influence of prenatal androgens contribute to the sexual dimorphism in hand and digit lengths.
Topics: Female; Fingers; Functional Laterality; Humans; Infant; Male; Reproducibility of Results; Sex Characteristics
PubMed: 34040007
DOI: 10.1038/s41598-021-89590-w -
Transfusion and Apheresis Science :... Dec 2020The Newcomb-Benford law - also known as the "law of anomalous numbers" or, more commonly, Benford's law - predicts that the distribution of the first significant digit... (Review)
Review
The Newcomb-Benford law - also known as the "law of anomalous numbers" or, more commonly, Benford's law - predicts that the distribution of the first significant digit of random numbers obtained from mixed probability distributions follows a predictable pattern and reveals some universal behavior. Specifically, given a dataset of empirical measures, the likelihood of the first digit of any number being 1 is ∼30 %, ∼18 % for 2, 12.5 % for 3 and so on, with a decreasing probability all the way to number 9. If the digits were distributed uniformly, all the numbers 1 through 9 would have the same probability to appear as the first digit in any given empirical random measurement. However, this is not the case, as this law defies common sense and seems to apply seamlessly to large data. The use of omics technologies and, in particular, metabolomics has generated a wealth of big data in the field of transfusion medicine. In the present meta-analysis, we focused on previous big data from metabolomics studies of relevance to transfusion medicine: one on the quality of stored red blood cells, one on the phenotypes of transfusion recipients, i.e. trauma patients suffering from trauma and hemorrhage, and one of relevance to the 2020 SARS-COV-2 global pandemic. We show that metabolomics data follow a Benford's law distribution, an observation that could be relevant for future application of the "law of anomalous numbers" in the field of quality control processes in transfusion medicine.
Topics: COVID-19; Humans; Metabolomics; Pandemics; SARS-CoV-2
PubMed: 33246837
DOI: 10.1016/j.transci.2020.103019 -
American Journal of Audiology Dec 2020Purpose The dichotic digits test (DDT) is commonly administered in clinical and research settings, but it is not well understood how performance changes in aging. The...
Purpose The dichotic digits test (DDT) is commonly administered in clinical and research settings, but it is not well understood how performance changes in aging. The purpose of this study is to determine the 5-year change on the free recall task and right ear advantage (REA) in a population-based cohort and factors associated with change. Method Participants in the population-based Epidemiology of Hearing Loss Study, who completed the DDT during the fourth (2009-2010) and fifth (2013-2016) examination periods were included ( = 865, = 72.8 years at baseline). Free recall DDT was administered using 25 sets of triple-digit pairs presented at 70 dB HL. The REA was calculated by subtracting the score in the left ear from the score in the right ear. Results In 5 years, most participants (62.4%) declined on free recall performance (mean decline = 3.0% [4.5 digits], < .01). In age-sex-adjusted models, higher baseline scores, hearing impairment, and lower education were significantly associated with increased risk of decline. An REA at baseline (76.8%) and follow-up (77.9%) was common. Half of participants (50.6%) had a 5-year REA widening ( = 1.9% [1.4 digits], = .01). Older age, but not hearing impairment, was associated with increased risk of REA widening. Conclusions The 5-year decline on free recall recognition performance was not associated with age but was associated with hearing impairment, whereas the 5-year widening of REA was associated with age but not hearing impairment. These results indicate that the REA may be a more sensitive measure of aging of the central auditory system than free recall performance.
Topics: Aged; Aging; Auditory Perception; Cohort Studies; Dichotic Listening Tests; Hearing Loss; Humans; Mental Recall; Prohibitins
PubMed: 32976033
DOI: 10.1044/2020_AJA-20-00098 -
Computational Intelligence and... 2022Classification of isolated digits is the basic challenge for many speech classification systems. While a lot of work has been carried out on spoken languages, only...
Classification of isolated digits is the basic challenge for many speech classification systems. While a lot of work has been carried out on spoken languages, only limited research work on spoken English digit data has been reported in the literature. The paper proposes an intelligent-based system based on deep feedforward neural network (DFNN) with hyperparameter optimization techniques, an ensemble method; random forest (RF), and a regression method; gradient boosting (GB) for the classification of spoken digit data. The paper investigates different machine learning (ML) algorithms to determine the best method for the classification of spoken English digit data. The DFNN classifier outperformed the RF and GB classifiers on the public benchmark spoken English digit data and achieved 99.65% validation accuracy. The outcome of the proposed model performs better compared to existing models with only traditional classifiers.
Topics: Algorithms; Deep Learning; Language; Machine Learning; Neural Networks, Computer
PubMed: 36211015
DOI: 10.1155/2022/3364141 -
NeuroImage Jan 2019The dominant model of number processing suggests the existence of a Number Form Area (NFA) in the inferior temporal gyrus (ITG) that supports the processing of Arabic...
The dominant model of number processing suggests the existence of a Number Form Area (NFA) in the inferior temporal gyrus (ITG) that supports the processing of Arabic digits as visual symbols of number. However, studies have produced inconsistent evidence for the presence and laterality of digit-specific ITG activity. Furthermore, whether any such activity relates to mathematical competence is unknown. This study investigated these two issues using functional magnetic resonance imaging. Thirty-two adults performed digit and letter detection tasks and reading and mathematics tests. During digit detection, participants determined whether digits were present in a string of letters (e.g., AH3NR versus AHTNR). During letter detection, participants determined whether letters were present in a string of digits (e.g., 93R78 versus 93478). Results showed four clusters in frontal, occipital, and temporal regions for digit detection, including a left ITG cluster. Five clusters in frontal, parietal, occipital, and temporal regions were associated with letter detection, including a left ITG cluster. Digit and letter-related ITG clusters were spatially distinct; however, a direct contrast of digit and letter processing did not reveal greater activity in the left ITG for digit detection. Whole brain correlations showed greater digit-related activity in the right ITG for participants with higher calculation skills, but there was no correlation between letter activity and calculation skills. Together, our results suggest functional localization, but not specialization, for digits in the left ITG and provide the first evidence of a relationship between calculation skills and digit processing in the right ITG.
Topics: Adolescent; Brain Mapping; Female; Functional Laterality; Humans; Magnetic Resonance Imaging; Male; Mathematical Concepts; Pattern Recognition, Visual; Temporal Lobe; Young Adult
PubMed: 30342974
DOI: 10.1016/j.neuroimage.2018.10.047 -
Cureus Sep 2022Super digits are a rare hand malformation, first described by Virchel Wood. Surgical intervention to try to make two fingers out of a super digit has been discouraged....
Super digits are a rare hand malformation, first described by Virchel Wood. Surgical intervention to try to make two fingers out of a super digit has been discouraged. Here, we present a variant of a super digit type IC2 and propose a revision of the characteristics in each super digit subtype. In our view, this adjustment in Wood's original description could facilitate the identification of super digits, which are a contraindication to syndactyly release.
PubMed: 36199652
DOI: 10.7759/cureus.28678 -
Dementia & Neuropsychologia 2019The digit span test is widely used to assess attention and working memory. It is a portable, relatively culture-free and frequently used test. However, the cultural...
UNLABELLED
The digit span test is widely used to assess attention and working memory. It is a portable, relatively culture-free and frequently used test. However, the cultural validity of this test, particularly in the Indian older population, is not well established.
OBJECTIVE
This study explores the usefulness of the digit span test for Indian older adults with different levels of education.
METHODS
Two hundred and fifty-eight community-dwelling healthy normal older adults formed the sample of this study. All study participants were screened using a semi-structured interview schedule, the modified MINI Screen, the Indian version of the Mini-Mental State Examination, a measure of activities of daily living and the digit span test administered verbally.
RESULTS
The results indicated that participants with higher educational level performed significantly better than low-educated participants on the digit span test. Participants with low education often struggled with the digit span test and resorted to guessing the digits.
CONCLUSION
Our study clearly demonstrates that the digit span test can be useful for educated participants. However, its usefulness and ecological validity is questionable for those with low education and low literacy, warranting future research.
PubMed: 31073387
DOI: 10.1590/1980-57642018dn13-010013 -
Frontiers in Neuroscience 2023The aim of the present study is to evaluate the effect of vibrotactile stimulation prior to repeated complex motor imagery of finger movements using the non-dominant...
PURPOSE
The aim of the present study is to evaluate the effect of vibrotactile stimulation prior to repeated complex motor imagery of finger movements using the non-dominant hand on motor imagery (MI) performance.
METHODS
Ten healthy right-handed adults (4 females and 6 males) participated in the study. The subjects performed motor imagery tasks with and without a brief vibrotactile sensory stimulation prior to performing motor imagery using either their left-hand index, middle, or thumb digits. Mu- and beta-band event-related desynchronization (ERD) at the sensorimotor cortex and an artificial neural network-based digit classification was evaluated.
RESULTS
The ERD and digit discrimination results from our study showed that ERD was significantly different between the vibration conditions for the index, middle, and thumb. It was also found that digit classification accuracy with-vibration (mean ± SD = 66.31 ± 3.79%) was significantly higher than without-vibration (mean ± SD = 62.68 ± 6.58%).
CONCLUSION
The results showed that a brief vibration was more effective at improving MI-based brain-computer interface classification of digits within a single limb through increased ERD compared to performing MI without vibrotactile stimulation.
PubMed: 37360173
DOI: 10.3389/fnins.2023.1152563 -
Royal Society Open Science Jan 2018We revisit digit reduction in the horse and propose that all five digits are partially present in the modern adult forelimb. Osteological descriptions of selected...
We revisit digit reduction in the horse and propose that all five digits are partially present in the modern adult forelimb. Osteological descriptions of selected tetradactyl, tridactyl and monodactyl equids demonstrate the evolution of the forelimb. Histological, osteological and palaeontological evidence suggest that the distal forelimb is more complex than traditionally conceived. The current understanding is that the horse distal forelimb consists of one complete digit (III) and two reduced splint metacarpals (II and IV). Metacarpals II and IV each exhibit a ventral ridge, which we suggest represents the undifferentiated digits I and V. These ridges are present in the tridactyl , but are absent in the tetradactyl The carpal articulations of the five metacarpals match those of pentadactyl taxa. Distally, the frog, a V-shaped structure on the ventral hoof represents digits II and IV, and the wings and hoof cartilages of the distal phalanx are digits I and V. We relate this revised interpretation of the forelimb to Laetoli footprints, and suggest the side impressions are created from the hooves of I and V, rather than from II and IV. We show shades of pentadactyly within the manus.
PubMed: 29410871
DOI: 10.1098/rsos.171782