scholarly journals Quantitative heterodonty in Crocodylia: assessing size and shape across modern and extinct taxa

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6485 ◽  
Author(s):  
Domenic C. D’Amore ◽  
Megan Harmon ◽  
Stephanie K. Drumheller ◽  
Jason J. Testin
Keyword(s):  
Regression Analysis ◽  
High Frequency ◽  
Prey Size ◽  
Dental Morphology ◽  
Minimal Processing ◽  
Skull Shape ◽  
Size And Shape ◽  
Rearing Conditions ◽  
Components Analysis ◽  
Shape Variance

Heterodonty in Crocodylia and closely related taxa has not been defined quantitatively, as the teeth rarely have been measured. This has resulted in a range of qualitative descriptors, with little consensus on the condition of dental morphology in the clade. The purpose of this study is to present a method for the quantification of both size- and shape-heterodonty in members of Crocodylia. Data were collected from dry skeletal and fossil specimens of 34 crown crocodylians and one crocodyliform, resulting in 21 species total. Digital photographs were taken of each tooth and the skull, and the margins of both were converted into landmarks and semilandmarks. We expressed heterodonty through Foote’s morphological disparity, and a principal components analysis quantified shape variance. All specimens sampled were heterodont to varying degrees, with the majority of the shape variance represented by a ‘caniniform’ to ‘molariform’ transition. Heterodonty varied significantly between positions; size undulated whereas shape was significantly linear from mesial to distal. Size and shape appeared to be primarily decoupled. Skull shape correlated significantly with tooth shape. High size-heterodonty often correlated with relatively large caniniform teeth, reflecting a prioritization of securing prey. Large, highly molariform, distal teeth may be a consequence of high-frequency durophagy combined with prey size. The slender-snouted skull shape correlated with a caniniform arcade with low heterodonty. This was reminiscent of other underwater-feeding tetrapods, as they often focus on small prey that requires minimal processing. Several extinct taxa were very molariform, which was associated with low heterodonty. The terrestrial peirosaurid shared similarities with large modern crocodylian taxa, but may have processed prey differently. Disparity measures can be inflated or deflated if certain teeth are absent from the tooth row, and regression analysis may not best apply to strongly slender-snouted taxa. Nevertheless, when these methods are used in tandem they can give a complete picture of crocodylian heterodonty. Future researchers may apply our proposed method to most crocodylian specimens with an intact enough tooth row regardless of age, species, or rearing conditions, as this will add rigor to many life history studies of the clade.

scholarly journals Sexual dimorphism and skull size and shape in the highly specialized snake species, Aipysurus eydouxii (Elapidae: Hydrophiinae)

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11311
Author(s):  
Bartosz Borczyk ◽  
Łukasz Paśko ◽  
Jan Kusznierz ◽  
Stanisław Bury
Keyword(s):  
Sexual Dimorphism ◽  
Body Length ◽  
Prey Size ◽  
Feeding Habits ◽  
Skull Morphology ◽  
Data Set ◽  
Skull Shape ◽  
Size And Shape ◽  
Mandibular Fossa ◽  
Males And Females

Background Snakes exhibit sexual dimorphism in both head size and shape. Such differences are often attributed to different reproductive roles and feeding habits. We aim to investigate how sexual dimorphism is displayed in the highly specialised fish-egg-eating snake, Aipysurus eydouxii, by analysing two complementary features: body size and skull morphology. Methods We used data on body length, weight, and skull shape from 27 measurements of 116 males and females of A. eydouxii. We investigated both sexual dimorphism and allometric (multivariate and bi-variate) properties of skull growth in the analysed data set. Results We found that although there was female-biased sexual size dimorphism in body length, females were not heavier than males, contrary to what is commonly observed pattern among snakes. Moreover, females tend to possess relatively smaller heads than males. However, we only found very subtle differences in skull shape reflected in nasal width, mandibular fossa, quadrate crest and quadrate length. Discussion We suggest that the feeding specialisation in A. eydouxii does not allow for an increase in body thickness and the size of the head above a certain threshold. Our results may be interpreted as support for prey-size divergence as a factor driving skull dimorphism since such species in which the sexes do not differ in prey size also shows very subtle or no differences in skull morphology.

Abstract 13243: Diminished Daily Fluctuation of Heart Rate Variability in Patients with Chronic Kidney Disease

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Hisaki Makimoto ◽  
Katsuhito Fujiu ◽  
Kohei Shimizu ◽  
Eisuke Amiya ◽  
Kazuo Asada ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Regression Analysis ◽  
Kidney Disease ◽  
High Frequency ◽  
High Frequency Component ◽  
Control Group ◽  
Holter Monitor ◽  
Significant Difference ◽  
High Incidence ◽  
Circadian Fluctuation

Introduction: Autonomic dysfunction is well known in patients with chronic kidney disease (CKD) and linked with cardiac death. In spite of a high incidence of morning death in CKD patients, circadian fluctuation in parasympathetic activation have not been studied in CKD. Hypothesis: We assessed the hypothesis that the cardiac autonomic circadian fluctuation is impaired in patients with CKD. Methods: The study population consisted of consecutive 101 patients (54 males, 70±10 years old) with CKD who underwent 24-hour Holter monitor. As a control group, 134 age and sex matched cases (66 males, 68±10 years old) without CKD who also underwent Holter monitor were recruited. Patients with diabetes orβ-blocker therapy were excluded. The high frequency component (HF), which reflected parasympathetic activity, and the low frequency to high frequency ratio (L/H ratio), which reflected, in part, sympathetic activity, were evaluated. To evaluate the contribution of CKD and other parameters to the cardiac autonomic fluctuation, the night (6PM-6AM) to day (6AM-6PM) ratio of HF and L/H ratio were analyzed utilizing a regression analysis. Results: The L/H ratio showed no significant difference during the night between the two groups, in contrast to the significant difference during the daytime. Patients with CKD showed significantly lower HF during the night as compared to control cases (P<0.05), although the daytime HF was not significantly different between the groups (Figure). Multivariate regression analysis demonstrated that CKD was independently associated with a lower night-to-day ratio of the HF and a higher night-to-day ratio of the L/H ration, even with the adjustment of age and comorbid hypertension. Conclusions: Our findings suggest that cardiac autonomic fluctuation is impaired in CKD patients. Whether a deterioration of autonomic activation might explain the high incidence of morning death in CKD patients needs to be clarified in future studies.

scholarly journals The wireless energy transfer (WET) using ultra high frequency (UHF) for human body implant recharging

2018 ◽  
Vol 43 ◽  
pp. 01027
Author(s):  
Fahmy Rinanda Saputri ◽  
Sunarno ◽  
Memory Motivanisman Waruwu ◽  
Rony Wijaya
Keyword(s):  
Energy Transfer ◽  
Human Body ◽  
High Frequency ◽  
Wireless Energy Transfer ◽  
Ultra High Frequency ◽  
Size And Shape ◽  
Uhf Band

The wireless energy transfer (wet) is widely used in many fields. In particularly for medical, this technique can be implemented to an electronic human body implant recharging. The possible size and shape of the receiver antenna in the experiment before still become a problem. Using Yagi-Uda model antenna for the transmitter unit in ultra-high frequency (UHF) band, this paper refers to design a receiver antenna for implemented as a human implant recharging. The receiver antenna has successfully designed in minimal with its size and shape of the designed antenna is about 1.44 cm3.

Interaction between searching cost and growth of the bivalve-feeder Halla okudai under rearing conditions, in relation to prey size

2000 ◽  
Vol 66 (5) ◽  
pp. 908-914 ◽  
Author(s):  
Hidetoshi Saito ◽  
Hiromichi Imabayashi ◽  
Koichiro Kawai
Keyword(s):  
Prey Size ◽  
Rearing Conditions

Prey capture and processing behaviors vary with prey size and shape in Australian and subantarctic fur seals

2015 ◽  
Vol 32 (2) ◽  
pp. 568-587 ◽  
Author(s):  
David P. Hocking ◽  
Erich M. G. Fitzgerald ◽  
Marcia Salverson ◽  
Alistair R. Evans
Keyword(s):  
Prey Capture ◽  
Prey Size ◽  
Size And Shape ◽  
Fur Seals ◽  
Subantarctic Fur Seals

scholarly journals Molecular quantification of differential ingestion and particle trapping rates by the appendicularian Oikopleura dioica as a function of prey size and shape

2007 ◽  
Vol 52 (1) ◽  
pp. 416-427 ◽  
Author(s):  
Christofer Troedsson ◽  
Marc E. Frischer ◽  
Jens C. Nejstgaard ◽  
Eric M. Thompson
Keyword(s):  
Prey Size ◽  
Particle Trapping ◽  
Oikopleura Dioica ◽  
Size And Shape

Morphology and genetics concur that Anoura carishina is a synonym of Anoura latidens (Chiroptera, Glossophaginae)

Mammalia ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Camilo A. Calderón-Acevedo ◽  
Miguel E. Rodríguez-Posada ◽  
Nathan Muchhala
Keyword(s):  
Principal Components Analysis ◽  
Principal Components ◽  
Phylogenetic Analyses ◽  
Similar Species ◽  
Dental Morphology ◽  
The Third ◽  
Triangular Shape ◽  
Components Analysis ◽  
Taxonomic Groups ◽  
Anoura Geoffroyi

Abstract Anoura carishina was described based on cranial and dental morphology, but the original analyses did not include Anoura latidens, a similar species of Anoura. We used morphological, morphometric, and genetic analyses to evaluate the taxonomic identity of A. carishina. We performed a principal components analysis to evaluate the correspondence between morphological and taxonomic groups for 260 specimens of large-bodied Anoura (A. carishina, Anoura geoffroyi, A. latidens, and Anoura peruana), and statistically analyzed traits diagnostic for A. latidens, including (1) morphology of the third upper premolar (P4), (2) size of the second (P3) and third (P4) upper premolars, and (3) angle formed by the maxillary toothrows. We find that A. latidens and A. carishina are indistinguishable, and share several characters lacking in A. geoffroyi, including a P4 with triangular shape, an under-developed anterobasal cusp in the P3, a smaller braincase, and a shorter rostrum. Phylogenetic analyses using ultra-conserved elements infer that the holotype and two paratype specimens of A. carishina are paraphyletic and nested within A. latidens, while one paratype diagnosable by morphology as A. geoffroyi nests within A. geoffroyi samples. We demonstrate that A. carishina should be considered a junior synonym of A. latidens, updating the distribution of the latter.

scholarly journals Optimized indoor daylight for tropical dense urban environments

2017 ◽  
Vol 17 (3) ◽  
pp. 87-102 ◽  
Author(s):  
Iara Gonçalves dos Santos ◽  
Thomas Auer ◽  
Roberta Vieira Gonçalves de Souza
Keyword(s):  
Regression Analysis ◽  
Performance Assessment ◽  
Urban Environment ◽  
High Frequency ◽  
Urban Areas ◽  
Urban Environments ◽  
Cardinal Directions ◽  
Daylight Performance ◽  
Sky Conditions

Abstract Studies using metrics related to dynamic sky conditions for indoor daylight performance assessment in urban environment are rare in tropical latitudes. This study applied one of these metrics, the spatial Daylight Autonomy (sDA 300,50% ≥75%, IES LM 83-12) for Cuiabá (15ºS, 56ºW, Brazil), a savanna climate city with a high frequency of partly cloudy skies. Parametric simulations were used to investigate the availability of daylight in dense urban areas. So daylight conditions inside a reference room with varied depths located within a continuous urban canyon were simulated with Radiance/Daysim in Grasshopper/Honeybee. Dimensions of the street and heights of front buildings (obstructions) are also varied in order to observe the relation between the sky angle and the sDA, for the four main cardinal directions. The results of regression analysis for this case study showed that among all evaluated parameters, room depth tended to be the most relevant for the optimization of indoor daylight. Finally, limitations of this approach and opportunities for further investigations were discussed.

Perceptual-Phonetic Predictors of Single-Word Intelligibility

2000 ◽  
Vol 43 (6) ◽  
pp. 1451-1465 ◽  
Author(s):  
Tara L. Whitehill ◽  
Valter Ciocca
Keyword(s):  
Young Adults ◽  
Regression Analysis ◽  
Cerebral Palsy ◽  
Principal Components Analysis ◽  
Principal Components ◽  
Short Vowel ◽  
Single Word ◽  
Intelligibility Test ◽  
Components Analysis ◽  
Phonetic Contrasts

This study investigated the perceptual-phonetic predictors of intelligibility in Cantonese speakers with dysarthria. The speakers were 20 young adults with cerebral palsy. The listener group consisted of 12 native Cantonese speakers. A single-word intelligibility test was constructed, based on 17 phonetic contrasts. There were no significant differences in intelligibility for gender, age, or type of cerebral palsy. A regression analysis showed that intelligibility could be predicted with 97% accuracy by 5 out of the 6 most problematic contrasts. Three contrasts (glottal vs. null, final vs. null, and long vs. short vowel) predicted variation on an independent intelligibility measure obtained for the same speakers with 84% accuracy. Principal components analysis derived 4 components, which accounted for 81% of the variance in the 17 contrasts. Physiological explanations and language-specific contributions to speech disorder in this group of speakers are discussed.

Dental Condition of Two Tribes of Taiwan Aborigines-Ami and Atayal

1977 ◽  
Vol 56 (2) ◽  
pp. 117-127 ◽  
Author(s):  
Khang-Lee Liu
Keyword(s):  
Dental Caries ◽  
Periodontal Disease ◽  
High Frequency ◽  
Low Frequency ◽  
Tooth Size ◽  
Dental Morphology ◽  
Sex Dimorphism ◽  
Taiwan Aborigines ◽  
Low Incidence

A low incidence of dental caries, periodontal disease, and malocclusion was demonstrated by this study of 166 Ami and 128 Atayal Taiwan aborigine adolescents. As for dental morphology, a high frequency of shovel-shaped incisors and Carabelli's trait but a relatively low frequency of protostylid were noticed as well as the sex dimorphism of tooth size.

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