scholarly journals The impact of allometry on vomer shape and its implications for the taxonomy and cranial kinesis of crown-group birds

2020 ◽  
Author(s):  
Olivia Plateau ◽  
Christian Foth

AbstractCrown birds are subdivided into two main groups, Palaeognathae and Neognathae, that can be distinguished, among others, by the organization of the bones in their pterygoid-palatine complex (PPC). Shape variation to the vomer, which is the most anterior part of the PPC, was recently analysed by Hu et al. (2019) with help of geometric morphometrics to discover morphological differences between palaeognath and neognath birds. Based on this study, the vomer was identified as sufficient to distinguish the two main groups (and even more inclusive neognath groups) and their cranial kinetic system. As there are notable size differences between the skulls of palaeognaths and neognaths, we here investigate the impact of allometry on vomeral shape and its implication for taxonomic classification by re-analysing the data of the previous study. Different types of multivariate statistical analyses reveal that taxonomic identification based on vomeral shape is strongly impaired by allometry, as the error of correct identification is high when shape data is corrected for size. This finding is evident by a great overlap between palaeognath and neognath subclades in morphospace. The correct identification is further influenced by the convergent presence of a flattened vomeral morphotype in multiple neognath subclades. As the evolution of cranial kinesis has been linked to vomeral shape in the original study, the existing correlation between shape and size of the vomer across different bird groups found in the present study questions this conclusion. In fact, cranial kinesis in crown birds results from the loss of the jugal-postorbital bar in the temporal region and ectopterygoid in the PPC and the combination of a mobilized quadrate-zygomatic arch complex and a flexible PPC. Therefore, we can conclude that the vomer itself is not a suitable proxy for exploring the evolution of cranial kinesis in crown birds and their ancestors.

2020 ◽  
Vol 16 (4) ◽  
pp. 715-729
Author(s):  
T.N. Savina

Subject. To achieve a high level of economic security is a key priority of national development. Employment reveals one of the most important aspects of social development of the individual that is associated with his or her needs satisfaction in the sphere of employment and is boon to economic security. Objectives. The purpose of the study is to show the impact of unemployment on economic security in employment. Methods. I apply such scientific methods as dialectical, historical and logical unity, structural and functional analysis, traditional techniques of economic analysis and synthesis. The methods of multivariate statistical and comparative analysis serve as a methodological basis of the study. To determine the indicator of unemployment, I use the band theory. Results. I underpin the growing role of employment in ensuring economic security. The paper presents a comprehensive assessment of the unemployment status and a comparative analysis of the indicator in the Republic of Mordovia, the Volga Federal District, and the Russian Federation as a whole. I identify trends in the average duration of unemployment, show the distribution of unemployed by level of education and age groups. Conclusions. The average annual unemployment rate in the Republic of Mordovia is lower than in Russia and the Volga Federal District. The findings may be useful for public authorities to substantiate their employment policy at both macro- and meso-levels, for designing programs and strategies for socio-economic development of regions and the social security doctrine, as well as in practical activities of employment services.


1986 ◽  
Vol 18 (9) ◽  
pp. 1189-1207
Author(s):  
B Ó Huallacháin

The conventional approach to assessing structural change in regional input – output tables is to measure the impact of coefficient change on the estimation of outputs and multipliers. The methods developed and tested in this paper focus exclusively on the coefficients. Univariate and multivariate statistical analyses can be used to identify and measure various types of changes ranging from coefficient instability to changes in interindustry relationships as a system. A distinction is made between structural changes in input relationships and those in output relationships. The methods are tested by using Washington State data for the years 1963 and 1967. The results are compared with previous analyses of change in these data.


2011 ◽  
Author(s):  
Daisuke Hibino ◽  
Yutaka Hojyo ◽  
Hiroyuki Shindo ◽  
Thuy Do ◽  
Aasutosh Dave ◽  
...  

2021 ◽  
Vol 11 (13) ◽  
pp. 5895
Author(s):  
Kristina Serec ◽  
Sanja Dolanski Babić

The double-stranded B-form and A-form have long been considered the two most important native forms of DNA, each with its own distinct biological roles and hence the focus of many areas of study, from cellular functions to cancer diagnostics and drug treatment. Due to the heterogeneity and sensitivity of the secondary structure of DNA, there is a need for tools capable of a rapid and reliable quantification of DNA conformation in diverse environments. In this work, the second paper in the series that addresses conformational transitions in DNA thin films utilizing FTIR spectroscopy, we exploit popular chemometric methods: the principal component analysis (PCA), support vector machine (SVM) learning algorithm, and principal component regression (PCR), in order to quantify and categorize DNA conformation in thin films of different hydrated states. By complementing FTIR technique with multivariate statistical methods, we demonstrate the ability of our sample preparation and automated spectral analysis protocol to rapidly and efficiently determine conformation in DNA thin films based on the vibrational signatures in the 1800–935 cm−1 range. Furthermore, we assess the impact of small hydration-related changes in FTIR spectra on automated DNA conformation detection and how to avoid discrepancies by careful sampling.


2015 ◽  
Author(s):  
Fabián Vera ◽  
Casee Lemons ◽  
Ming Zhong ◽  
William D. Holcomb ◽  
Randy F. LaFollette

Abstract This study compares reservoir characteristics, completion methods and production for 431 wells in 6 counties producing from the Wichita-Albany reservoir to assess major factors in production optimization and derive ultimate recovery estimates. The purpose of the study is to analyze completion design patterns across the study area by combining public and proprietary data for mining. Integrating several analyses of different nature and their respective methods like statistics, geology and engineering create a modern approach as well as a more holistic point of view when certain measurements are missing from the data set. Furthermore, multivariate statistical analysis allows modeling the impact of particular completion and stimulation parameters on the production outcome by averaging out the impact of all other variables in the system. In addition to completion type, more than 18 predictor variables were examined, including treatment parameters such as fracture fluid volume, year of completion, cumulative perforated length, proppant type, proppant amount, and county location, among others. In this sense, this contribution seems unique in unifying statistical, engineering, and geological perspectives into a singular point of view. This work also provides complementary views for well production consideration.


2013 ◽  
Vol 1 (2) ◽  
pp. 957-1000 ◽  
Author(s):  
M. Fressard ◽  
Y. Thiery ◽  
O. Maquaire

Abstract. The objective of this paper is to assess the impact of the datasets quality for the landslide susceptibility mapping using multivariate statistical modelling methods at detailed scale. This research is conducted in the Pays d'Auge plateau (Normandy, France) with a scale objective of 1/10000, in order to fit the French guidelines on risk assessment. Five sets of data of increasing quality (considering accuracy, scale fitting, geomophological significance) and cost of acquisition are used to map the landslide susceptibility using logistic regression. The best maps obtained with each set of data are compared on the basis of different statistical accuracy indicators (ROC curves and relative error calculation), linear cross correlation and expert opinion. The results highlights that only high quality sets of data supplied with detailed geomorphological variables (i.e. field inventory and surficial formations maps) can predict a satisfying proportion of landslides on the study area.


2009 ◽  
Vol 100 (1) ◽  
pp. 19-26 ◽  
Author(s):  
M.L. Lyra ◽  
L.M. Hatadani ◽  
A.M.L. de Azeredo-Espin ◽  
L.B. Klaczko

AbstractCochliomyia hominivoraxandCochliomyia macellariaare endemic Neotropical Calliphoridae species. The former causes severe myiasis in hosts while the latter is Sarcosaprophagous, but commonly found as a second invader in wounds. Due to the morphological similarity between them and the potential losses thatC. hominivoraxrepresents for cattle breeders, the rapid and correct identification of these two species is very important. In addition to a correct identification of these species, a good knowledge ofC. hominivoraxbiology can be helpful for designing control programs. We applied geometric morphometric methods to assess wing differences betweenC. hominivoraxandC. macellariaand conduct a preliminary analysis of wing morphological variation inC. hominivoraxpopulations. Canonical variate analysis, using wing shape data, correctly classified 100% of the individuals analyzed according to sex and species. This result demonstrates that wing morphometry is a simple and reliable method for identifyingC. hominivoraxandC. macellariasamples and can be used to monitorC. hominivorax. Both species show sexual dimorphism, but inC. hominivoraxit is magnified. We suggest that this may reflect different histories of selection pressures operating on males and females. Significant differences in wing size and shape were obtained amongC. hominivoraxpopulations, with little correlation with latitude. This result suggests that wing variation is also a good morphological marker for studying population variation inC. hominivorax.


Author(s):  
Ting Yue ◽  
Ruyin Long ◽  
Junli Liu ◽  
Haiwen Liu ◽  
Hong Chen

With the improvement of living quality and the increase of energy consumption of residents, their energy conservation behavior (ECB) plays an increasingly important role in energy conservation and emission reduction. As a kind of environmental behavior, ECB of residents is a complicated process. In this paper, ECB is divided into four types, considering habit adjustment, quality threshold, efficiency investment, and interpersonal facilitation. A comprehensive conceptual framework is built, adding perception about energy conservation results (PER) and contextual factors from a new perspective. Based on a survey in Jiangsu province of China, this paper examines the impact of intention on behavior under the moderation of contextual factors, as well as the effect of perception of energy-conservation results on intention and ECB by means of multivariate statistical analysis. The results show that the intention of energy conservation is the determinant of behavior, but it does not well transform into behavior, especially into quality threshold and interpersonal facilitation behavior. Different contextual factors have positive effects on the relationship of intention and different behavior. However, modulating effects of contextual factors as amplifiers do not function effectively due to their low rating scores. PER has a positive impact on intention but not on all types of ECB. Finally, this paper presents important implications for policy makers to optimize energy conservation policy.


Sign in / Sign up

Export Citation Format

Share Document