Assessing the completeness of the fossil record: comparison of different methods applied to parareptilian tetrapods (Vertebrata: Sauropsida)

Paleobiology ◽  
2016 ◽  
Vol 42 (4) ◽  
pp. 680-695 ◽  
Author(s):  
Antoine Verrière ◽  
Neil Brocklehurst ◽  
Jörg Fröbisch
Keyword(s):  
Body Size ◽  
Strong Correlation ◽  
Fossil Record ◽  
Data Sets ◽  
Phylogenetic Information ◽  
Phylogenetic Data ◽  
Skeletal Material ◽  
Two Measures ◽  
The Mean ◽  
The Impact

AbstractAs paleontological studies are generally distorted by gaps and biases in the fossil record, it is important to assess its completeness. Here we address the fossil record of Parareptilia, a Permian–Triassic amniote clade, applying two measures of specimen completeness: the skeletal completeness metric (SCM) and the character completeness metric (CCM). The SCM quantifies how much of the skeletal material of a taxon is preserved, whereas the CCM measures the amount of phylogenetic information available. The latter was implemented using two different approaches. In this study, we compare three completeness metrics. Two CCM implementations show a strong correlation with each other, but only the second implementation of the CCM correlates significantly with the SCM, possibly due to character selection in phylogenetic data sets. There is no correlation between diversity of parareptiles and their completeness, implying that the observed fluctuations in diversity are not driven by the completeness of the fossils. The mean completeness of parareptiles through time is consistently high compared with previously studied tetrapod clades, suggesting that most parareptile taxa are based on reasonably complete specimens. Clade-specific differences reveal no link between body size and completeness. However, the analyses confirm the impact of ecology, with aquatic mesosaurids being better preserved than terrestrial taxa.

scholarly journals DOES CASSINI ALLOW ONE TO MEASURE RELATIVISTIC ORBITAL EFFECTS IN THE SATURNIAN SYSTEM OF SATELLITES?

2007 ◽  
Vol 16 (01) ◽  
pp. 11-17 ◽  
Author(s):  
LORENZO IORIO
Keyword(s):  
Data Sets ◽  
Zonal Harmonics ◽  
Low Degree ◽  
Saturnian System ◽  
Order Of Magnitude ◽  
General Relativistic ◽  
The Mean ◽  
Natural Satellites ◽  
The Impact

In this paper we address the following question: do the recent advances in the orbit determination of the major natural satellites of Saturn obtained with the analysis of the first data sets from the Cassini spacecraft allow to detect the general relativistic gravitoelectric orbital precessions of the mean longitudes of such moons? The answer is still negative. The present-day down-track accuracy is adequate for Mimas, Enceladus, Thetys, Dione, Rhea and Titan and inadequate for Hyperion, Iapetus and Phoebe. Instead, the size of the systematic errors induced by the mismodeling in the key parameters of the Saturnian gravitational field like the even zonal harmonics Jℓ are larger than the relativistic down-track shifts by about one order of magnitude, mainly for the inner satellites like Mimas, Enceladus, Thetys, Dione, Rhea, Titan and Hyperion. Instead, Iapetus and Phoebe are not notably affected by such kind of perturbations. Moreover, the bias due to the uncertainty in Saturn's GM is larger than the relativistic down-track effects for all such moons up to two orders of magnitude (Phoebe). Thus, it would be impossible to separately analyze the mean longitudes of each satellite. Proposed linear combinations of the satellites' mean longitudes would allow to cancel out the impact of the mismodeling in the low-degree even zonal harmonics and GM, but the combined down-track errors would be larger than the combined relativistic signatures by a factor 103.

scholarly journals Impact of gray matter signal regression in resting state and language task functional networks

2016 ◽  
Author(s):  
Luis C. T. Herrera ◽  
Gabriela Castellano ◽  
Ana C. Coan ◽  
M. Ludwing ◽  
C. L. César
Keyword(s):  
Community Structure ◽  
Gray Matter ◽  
Resting State ◽  
Mean Value ◽  
Clustering Coefficient ◽  
Data Sets ◽  
Before And After ◽  
The Mean ◽  
Graph Parameters ◽  
The Impact

AbstractA network analysis of the resting state (RS) and language task (LT) of fRMI data sets is presented. Specifically, the analysis compares the impact of the global signal regression of gray matter signal on the graph parameters and community structure derived of functional data. It was found that, without gray matter signal regression (GSR), the group comparison showed no significant changes of the global metrics between the two conditions studied. With gray matter signal regression, significant differences between the global (local) metrics for the conditions were obtained. The mean degree, the clustering coefficient of the network and the mean value of the local efficiency were metrics with significant changes. The community structure of group connectivity matrices was explored for both conditions (RS and LT) and for different preprocessing steps. When gray matter signal regression was performed, small changes of the community structure were observed. Approximately, the same regions were classified in the same communities before and after GSR. This means, that the community structure of the data is weakly affected by this preprocessing step. The modularity index presented significant changes between conditions (RS and LT) and between different preprocessing pipeline.

scholarly journals Upright walking has driven unique vascular specialization of the hominin ilium

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12240
Author(s):  
Dexter Zirkle ◽  
Richard S. Meindl ◽  
C. Owen Lovejoy
Keyword(s):  
Body Size ◽  
Fossil Record ◽  
Great Apes ◽  
Anterior Inferior Iliac Spine ◽  
Canal System ◽  
Modern Humans ◽  
Fossil Hominins ◽  
Report Analysis ◽  
The Mean ◽  
African Great Apes

Background A novel physis in hominins modulates broadening and shortening of the ilium. We report analysis of a vascular canal system whose origin may be associated with this physis and which appears to be also unique to hominins. Its presence is potentially identifiable in the fossil record by its association with a highly enlarged foramen that is consistently present in modern humans and hominin fossils. Methods We measured the diameter of this foramen in humans, fossil hominins, and African great apes and corrected for body size. Results The mean relative human foramen diameter is significantly greater than those of either Pan or Gorilla. Moreover, eight of the nine values of the Cohen’s d for these differences in ratios are highly significant and support the ordering of magnitudes: Pan < Gorilla < Homo. The relative foramen diameter of A.L. 288-1 is above the 75th percentile of all other hominoids and at the high end of humans. The foramen is also present in ARA-VP-6/500. Conclusions We posit that the presence and significant enlargement of this foramen in fossils can reasonably serve as an indicator that its anterior inferior iliac spine emerged via the unique hominin physis. The foramen can therefore serve as an indicator of hominin iliac ontogenetic specialization for bipedality in fossil taxa.

Asteroid and Comet Impact Speeds upon Mars: Significance for Panspermia and the Supply of Organics

1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel
Keyword(s):  
Probability Distributions ◽  
Regions Of Interest ◽  
Significant Fraction ◽  
Organic Chemicals ◽  
Impact Speed ◽  
The Mean ◽  
The Impact

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.

Sound Production Treatment for Acquired Apraxia of Speech: An Examination of Dosage in Relation to Probe Performance

2020 ◽  
pp. 1-16
Author(s):  
Julie L. Wambaugh ◽  
Lydia Kallhoff ◽  
Christina Nessler
Keyword(s):  
Retrospective Analysis ◽  
Sound Production ◽  
Apraxia Of Speech ◽  
Practice Schedule ◽  
Practice Schedules ◽  
Baseline Performance ◽  
The Mean ◽  
Number Of Treatment ◽  
The Impact

Purpose This study was designed to examine the association of dosage and effects of Sound Production Treatment (SPT) for acquired apraxia of speech. Method Treatment logs and probe data from 20 speakers with apraxia of speech and aphasia were submitted to a retrospective analysis. The number of treatment sessions and teaching episodes was examined relative to (a) change in articulation accuracy above baseline performance, (b) mastery of production, and (c) maintenance. The impact of practice schedule (SPT-Blocked vs. SPT-Random) was also examined. Results The average number of treatment sessions conducted prior to change was 5.4 for SPT-Blocked and 3.9 for SPT-Random. The mean number of teaching episodes preceding change was 334 for SPT-Blocked and 179 for SPT-Random. Mastery occurred within an average of 13.7 sessions (1,252 teaching episodes) and 12.4 sessions (1,082 teaching episodes) for SPT-Blocked and SPT-Random, respectively. Comparisons of dosage metric values across practice schedules did not reveal substantial differences. Significant negative correlations were found between follow-up probe performance and the dosage metrics. Conclusions Only a few treatment sessions were needed to achieve initial positive changes in articulation, with mastery occurring within 12–14 sessions for the majority of participants. Earlier occurrence of change or mastery was associated with better follow-up performance. Supplemental Material https://doi.org/10.23641/asha.12592190

Impact of changing rainfall conditions on surface and groundwater resources in an experimental watershed in Greece

2013 ◽  
Vol 12 (2) ◽  
pp. 119-125
Keyword(s):  
Groundwater Resources ◽  
Annual Runoff ◽  
Annual Rainfall ◽  
Rainfall Regime ◽  
Winter Rainfall ◽  
Rainfall Depth ◽  
Rainfall Volume ◽  
The Mean ◽  
Groundwater Reserves ◽  
The Impact

The present study concerns the impact of a change in the rainfall regime on surface and groundwater resources in an experimental watershed. The research is conducted in a gauged mountainous watershed (15.18 km2) that is located on the eastern side of Penteli Mountain, in the prefecture of Attica, Greece and the study period concerns the years from 2003 to 2008. The decrease in the annual rainfall depth during the last two hydrological years 2006-2007, 2007-2008 is 10% and 35%, respectively, in relation to the average of the previous years. In addition, the monthly distribution of rainfall is characterized by a distinct decrease in winter rainfall volume. The field measurements show that this change in rainfall conditions has a direct impact on the surface runoff of the watershed, as well as on the groundwater reserves. The mean annual runoff in the last two hydrological years has decreased by 56% and 75% in relation to the average of the previous years. Moreover, the groundwater level follows a declining trend and has dropped significantly in the last two years.

(Preprint)

2018 ◽  
Author(s):  
Natalia Banasik ◽  
Dariusz Jemielniak ◽  
Wojciech P?dzich
Keyword(s):  
Medical Condition ◽  
Extended Period ◽  
Well Being ◽  
Marginal Effect ◽  
Life Duration ◽  
Significant Difference ◽  
The Mean ◽  
Academic Teachers ◽  
Length Of Life ◽  
The Impact

BACKGROUND There have been mixed results of the studies checking whether prayers do actually extend the life duration of the people prayed for. Most studies on the topic included a small number of prayers and most of them focused on people already struggling with a medical condition. Intercessory prayer’s influence on health is of scholarly interest, yet it is unclear if its effect may be dependent on the number of prayers for a named individual received per annum. OBJECTIVE We sought to examine if there is a noticeable increased longevity effect of intercessory prayer for a named individual’s well-being, if he receives a very high number of prayers per annum for an extended period. METHODS We retrieved and conducted a statistical analysis of the data about the length of life for 857 Roman Catholic bishops, 500 Catholic priests, and 3038 male academics from the US, France, Italy, Poland, Brazil, and Mexico. We obtained information for these individuals who died between 1988 and 2018 from Wikidata, and conducted an observational cohort study. Bishops were chosen for the study, as they receive millions of individual prayers for well being, according to conservative estimates. RESULTS There was a main effect for occupation F(2, 4391) = 4.07, p = .017, ηp 2 = .002, with pairwise comparisons indicating significant differences between the mean life duration of bishops (M=30489) and of priests (M=29894), but none between the academic teachers (M=30147) and either of the other groups. A comparison analysis between bishops from the largest and the smallest dioceses showed no significant difference t(67.31)=1.61, p = .11. Our main outcome measure is covariance of the mean length of life in each of the categories: bishops, priests, academic teachers, controlled for nationality. CONCLUSIONS The first analysis proved that bishops live longer than priests, but due to a marginal effect size this result should be treated with caution. No difference was found between the mean length of life of bishops from the largest and the smallest dioceses. We found no difference between bishops and male academics. These results show that the impact of intercessory prayers on longevity is not observable.

scholarly journals Mean Empirical Likelihood Inference for Response Mean with Data Missing at Random

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Hanji He ◽  
Guangming Deng
Keyword(s):  
Empirical Likelihood ◽  
Missing At Random ◽  
Confidence Regions ◽  
Likelihood Inference ◽  
High Dimensional ◽  
Finite Sample ◽  
The Mean ◽  
Data Missing ◽  
Consistency And Asymptotic Normality ◽  
The Impact

We extend the mean empirical likelihood inference for response mean with data missing at random. The empirical likelihood ratio confidence regions are poor when the response is missing at random, especially when the covariate is high-dimensional and the sample size is small. Hence, we develop three bias-corrected mean empirical likelihood approaches to obtain efficient inference for response mean. As to three bias-corrected estimating equations, we get a new set by producing a pairwise-mean dataset. The method can increase the size of the sample for estimation and reduce the impact of the dimensional curse. Consistency and asymptotic normality of the maximum mean empirical likelihood estimators are established. The finite sample performance of the proposed estimators is presented through simulation, and an application to the Boston Housing dataset is shown.

scholarly journals Onchocerciasis control in Ghana (1974–2016)

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Nana-Kwadwo Biritwum ◽  
Dziedzom K. de Souza ◽  
Odame Asiedu ◽  
Benjamin Marfo ◽  
Uche Veronica Amazigo ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Vector Control ◽  
Control Strategy ◽  
Financial Support ◽  
Control Programme ◽  
Ivermectin Treatment ◽  
Mobile Community ◽  
The Mean ◽  
The Impact ◽  
Onchocerciasis Control

Abstract Background The control of onchocerciasis in Ghana started in 1974 under the auspices of the Onchocerciasis Control Programme (OCP). Between 1974 and 2002, a combination of approaches including vector control, mobile community ivermectin treatment, and community-directed treatment with ivermectin (CDTI) were employed. From 1997, CDTI became the main control strategy employed by the Ghana OCP (GOCP). This review was undertaken to assess the impact of the control interventions on onchocerciasis in Ghana between 1974 and 2016, since which time the focus has changed from control to elimination. Methods In this paper, we review programme data from 1974 to 2016 to assess the impact of control activities on prevalence indicators of onchocerciasis. This review includes an evaluation of CDTI implementation, microfilaria (Mf) prevalence assessments and rapid epidemiological mapping of onchocerciasis results. Results This review indicates that the control of onchocerciasis in Ghana has been very successful, with a significant decrease in the prevalence of infection from 69.13% [95% confidence interval) CI 60.24–78.01] in 1975 to 0.72% (95% CI 0.19–1.26) in 2015. Similarly, the mean community Mf load decreased from 14.48 MF/skin snip in 1975 to 0.07 MF/skin snip (95% CI 0.00–0.19) in 2015. Between 1997 and 2016, the therapeutic coverage increased from 58.50 to 83.80%, with nearly 100 million ivermectin tablets distributed. Conclusions Despite the significant reduction in the prevalence of onchocerciasis in Ghana, there are still communities with MF prevalence above 1%. As the focus of the GOCP has changed from the control of onchocerciasis to its elimination, both guidance and financial support are required to ensure that the latter goal is met.

scholarly journals Investigating the impact of pre-processing techniques and pre-trained word embeddings in detecting Arabic health information on social media

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yahya Albalawi ◽  
Jim Buckley ◽  
Nikola S. Nikolov
Keyword(s):  
Social Media ◽  
Deep Learning ◽  
Comprehensive Evaluation ◽  
Classification Problem ◽  
Data Sets ◽  
Word Embeddings ◽  
Data Set ◽  
Lower Accuracy ◽  
Health Related ◽  
The Impact

AbstractThis paper presents a comprehensive evaluation of data pre-processing and word embedding techniques in the context of Arabic document classification in the domain of health-related communication on social media. We evaluate 26 text pre-processings applied to Arabic tweets within the process of training a classifier to identify health-related tweets. For this task we use the (traditional) machine learning classifiers KNN, SVM, Multinomial NB and Logistic Regression. Furthermore, we report experimental results with the deep learning architectures BLSTM and CNN for the same text classification problem. Since word embeddings are more typically used as the input layer in deep networks, in the deep learning experiments we evaluate several state-of-the-art pre-trained word embeddings with the same text pre-processing applied. To achieve these goals, we use two data sets: one for both training and testing, and another for testing the generality of our models only. Our results point to the conclusion that only four out of the 26 pre-processings improve the classification accuracy significantly. For the first data set of Arabic tweets, we found that Mazajak CBOW pre-trained word embeddings as the input to a BLSTM deep network led to the most accurate classifier with F1 score of 89.7%. For the second data set, Mazajak Skip-Gram pre-trained word embeddings as the input to BLSTM led to the most accurate model with F1 score of 75.2% and accuracy of 90.7% compared to F1 score of 90.8% achieved by Mazajak CBOW for the same architecture but with lower accuracy of 70.89%. Our results also show that the performance of the best of the traditional classifier we trained is comparable to the deep learning methods on the first dataset, but significantly worse on the second dataset.

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