Geometric morphometrics of mandibular shape in the dwarf fat-tailed jerboa: relevancy for trinomial taxonomy

2020 ◽  
Author(s):  
Boris Kryštufek ◽  
Georgy Shenbrot ◽  
Tina Klenovšek ◽  
Franc Janžekovič
Keyword(s):  
Spatial Variation ◽  
Geometric Morphometrics ◽  
Independent Study ◽  
Glans Penis ◽  
Environmental Pressure ◽  
Taxonomic Information ◽  
Mandible Shape ◽  
Mandibular Morphology ◽  
The One ◽  
Null Expectation

Abstract We explore the pattern of spatial variation in mandibular morphology in relation to subspecific taxonomy in the dwarf fat-tailed jerboa, Pygeretmus pumilio. The unguided k-means clustering on mandible shape scores, partitioned populations into two clusters, corresponding to western and eastern populations. These clusters nearly perfectly matched the two subspecies groups (pumilio and potanini groups) recognized in an independent study based on the morphology of the glans penis. The mandible, although under environmental pressure, has retained a sufficient amount of taxonomic information to retrieve grouping closely resembling the one derived from a sexually selective trait. We recommend morphometrics of the mandible as a routine step in addressing variations in mammals at species and subspecies levels. We also stress the advantage of unsupervised k-clustering in testing null expectation in subspecies taxonomies. However, the power of this approach has its limitations and in our analysis, the k-clustering failed to retrieve subspecies in the potanini group.

Partial Amputation of Glans Penis During Mogen Clamp Circumcision

PEDIATRICS ◽  
1996 ◽  
Vol 97 (6) ◽  
pp. 906-907 ◽  
Author(s):  
Bruce S. Strimling
Keyword(s):  
United States ◽  
Numerical Data ◽  
The United States ◽  
The Other ◽  
Glans Penis ◽  
Partial Amputation ◽  
The One

Although no numerical data are available, the most common techniques for performing newborn circumcision in the United States involve the use of the Plastibell, the Gomco clamp, and the Mogen clamp, likely in that order. The Mogen clamp (see Fig 1 and 2) is the least familiar to most pediatricians. It has a number of advantages when compared with the other techniques: 1. the one size of the Mogen fits all; 2. it is the most rapid; 3. the Mogen instrument allows full visualization of exactly how much prepuce to remove. In Mogen circumcision however, the glans is not visualized before removal of the prepuce.

Numerical Investigation of a High Speed Centrifugal Compressor Impeller

2005 ◽  
Author(s):  
Shun Kang
Keyword(s):  
Secondary Flow ◽  
Flow Structure ◽  
Centrifugal Compressor ◽  
High Speed ◽  
Independent Study ◽  
Low Speed ◽  
Operation Conditions ◽  
Compressor Impeller ◽  
Secondary Flow Structure ◽  
The One

This paper presents the CFD simulations of a high speed centrifugal compressor impeller using the NUMECA Fine/Turbo software with the one equation turbulence model of Spalart-Allmaras. The simulations are validated via comparison with the experimental data. The computational grid densities are changed with the impeller tip size and a grid independent study is carried out. The flow physics of the compressor impeller is numerically studied in details, in particular, the formation of shocks and their effects on the 3D flow and the secondary flow structure are analyzed at different operation conditions, with comparison to low speed machines. It is found that the energy loss production is greatly affected by the shock waves and their interaction with the boundary layers in the inducer portion, while in the other portion, the secondary flow structure is globally the same as those in low speed machines.

scholarly journals Spatial variation in the stable isotopes of 13C and 15N and trophic position of Leporinus friderici (Characiformes, Anostomidae) in Corumbá Reservoir, Brazil

2007 ◽  
Vol 79 (1) ◽  
pp. 41-49 ◽  
Author(s):  
Alexandre L. Pereira ◽  
Evanilde Benedito ◽  
Cássia M. Sakuragui
Keyword(s):  
Stable Isotopes ◽  
Carbon Source ◽  
Isotopic Composition ◽  
Spatial Variation ◽  
Food Web ◽  
Trophic Level ◽  
Trophic Position ◽  
Trophic Levels ◽  
C3 Plants ◽  
The One

Stable isotopes of carbon (delta13C) and nitrogen (delta15N) were used to describe sources of energy and trophic position for adult Leporinus friderici in the area of the Corumbá Reservoir, Brazil. Samples were collected from April 1999 to March 2000. Spatial variations were not identified in the isotopic composition. The maximum and minimum contribution of C4 plants calculated integrating the variation of plants and fish were 47.7% and 2.4%, respectively. Among C3 plants, periphyton presented closer isotopic values to those observed for fishes, corresponding to an important carbon source. The proportion of ingested plant item is larger in rivers upstream from the reservoir (42.7%), which justifies the smaller trophic level among there. However, in the reservoir, the ingestion of fish was 81.4%, while ingested plants contributed with 18.6%. Downstream from the dam, participation of plant item was even smaller (14.4%). Although the trophic position calculated with diet data was proportional to the one calculated with delta15N values, the former elevated the trophic level of L. friderici in the food web, because estimated trophic positions were based on fish items belonging to the 2nd (a) and to the 3rd (b) trophic levels.

Geometric morphometrics meets metacommunity ecology: environment and lineage distribution affects spatial variation in shape

Ecography ◽  
2017 ◽  
Vol 41 (1) ◽  
pp. 90-100 ◽  
Author(s):  
Renan Maestri ◽  
Leandro Rabello Monteiro ◽  
Rodrigo Fornel ◽  
Thales Renato Ochotorena de Freitas ◽  
Bruce D. Patterson
Keyword(s):  
Spatial Variation ◽  
Geometric Morphometrics ◽  
Metacommunity Ecology ◽  
Lineage Distribution

scholarly journals Long-Term Dietary Restriction Leads to Development of Alternative Fighting Strategies

2021 ◽  
Vol 14 ◽  
Author(s):  
Jeanne Legros ◽  
Grace Tang ◽  
Jacques Gautrais ◽  
Maria Paz Fernandez ◽  
Séverine Trannoy
Keyword(s):  
Aggressive Behavior ◽  
Dietary Restriction ◽  
Food Resource ◽  
Behavioral Strategies ◽  
Environmental Pressure ◽  
Physical Attack ◽  
Set Up ◽  
The One

In competition for food, mates and territory, most animal species display aggressive behavior through visual threats and/or physical attacks. Such naturally-complex social behaviors have been shaped by evolution. Environmental pressure, such as the one imposed by dietary regimes, forces animals to adapt to specific conditions and ultimately to develop alternative behavioral strategies. The quality of the food resource during contests influence animals' aggression levels. However, little is known regarding the effects of a long-term dietary restriction-based environmental pressure on the development of alternative fighting strategies. To address this, we employed two lines of the wild-type Drosophila melanogaster Canton-S (CS) which originated from the same population but raised under two distinct diets for years. One diet contained both proteins and sugar, while the second one was sugar-free. We set up male-male aggression assays using both CS lines and found differences in aggression levels and the fighting strategies employed to establish dominance relationships. CS males raised on a sugar-containing diet started fights with a physical attack and employed a high number of lunges for establishing dominance but displayed few wing threats throughout the fight. In contrast, the sugar-free-raised males favored wing threats as an initial aggressive demonstration and used fewer lunges to establish dominance, but displayed a higher number of wing threats. This study demonstrates that fruit flies that have been raised under different dietary conditions have adapted their patterns of aggressive behavior and developed distinct fighting strategies: one favoring physical attacks, while the other one favoring visual threats.

scholarly journals Mandible shape in marsupial and placental carnivorous mammals: a morphological comparative study using geometric morphometrics

2011 ◽  
Vol 164 (4) ◽  
pp. 836-855 ◽  
Author(s):  
FRANCISCO J. PREVOSTI ◽  
GUILLERMO F. TURAZZINI ◽  
MARCOS D. ERCOLI ◽  
ERIKA HINGST-ZAHER
Keyword(s):  
Comparative Study ◽  
Geometric Morphometrics ◽  
Mandible Shape

scholarly journals On the Cauchy problem with an initial point lying on the boundary of ordinary differential equation’s domain of definition

2020 ◽  
Vol 65 (4) ◽  
pp. 636-648
Author(s):  
Vladimir V. Basov ◽  
◽  
Yurii A. Iljin ◽  
Keyword(s):  
Initial Value Problem ◽  
Initial Point ◽  
Polygonal Line ◽  
Independent Study ◽  
Comparison Theorems ◽  
Initial Value ◽  
Line Method ◽  
The Cauchy Problem ◽  
The One ◽  
The Right

In this paper we investigate the existence of solution of the initial-value problem with an initial point located at the boundary of the domain of definition for the first-order differential equation. This initial-value problem differs from the one accepted in classical theory, where the initial point is always internal for domain. Our aim is to find such conditions for the right-hand side of the equation and the boundary that would guarantee the existence or absence of this solution. In its previous article the authors used the standard Euler polygonal line method to solve this problem and described all cases when this method is used to get the desired answer. The polygonal line method, having certain advantages (constructibility, the ability to use a computer), requires for its implementation that both the equation and the domain of its definition meet certain restrictions, which inevitably narrows the class of acceptable equations. In this paper, we attempt to maximize the results obtained earlier, and for this purpose we use a completely different approach. The original equation is extended in such a way that the boundary initial-value problem becomes an ordinary internal initial-value problem, for which the standard Peano theorem is applied. To answer the question whether the solution of the modified initial-value problem is also the solution of the original boundary initial-value problem, so-called comparison theorems and differential inequalities are applied. This article is an independent study, not based on our previous work. For the sake of completeness, new proofs are given for previously obtained results, which are based on a new approach. As a result, we expanded the class of equations under consideration, removed the previous requirements for convexity and smoothness of boundary curves, and added cases that could not be considered using the polygonal line method. This work closes a certain gap that exists in the literature on the existence or absence of solutions to the boundary initial-value problem.

scholarly journals PROBLEM OF PROFESSIONAL IMAGE OF THE FOREIGN LANGUAGE TEACHER IN THE CONTEXT OF GLOBALIZATION

2019 ◽  
pp. 390-397
Author(s):  
L. I. Serman
Keyword(s):  
Higher Education ◽  
Foreign Language ◽  
Independent Study ◽  
Language Teachers ◽  
Foreign Languages ◽  
Easy Access ◽  
Language Teacher ◽  
The World ◽  
Professional Image ◽  
The One

More than any other profession, the teaching of foreign languages requires professionals with a special set of qualities. The article deals with the problem of the professional image of a foreign language teacher in the context of globalization processes in the field of higher education. The conditions in which didactics of languages and cultures fit into modern phenomena of globalization and valorization of universality are characterized. The situation with the teaching of foreign languages in universities of both Ukraine and the world is studied. The role and professional image of a foreign language teacher are analyzed. For this purpose, research was carried out by questioning the students. The results of the survey became the object of statistical analysis (quantitative method) and analysis of open responses and arguments (qualitative method). An attempt to find out methodological tactics for improving the foreign languages teaching in a globalizing environment is made. In the conditions of globalization of all spheres of public life, modern realities of the system of higher education change faster than ever before. The problem of teaching foreign languages as well as the role and image of a foreign language teacher is not the most acute. The ever-changing context of globalization and valorisation of universality dictates new demands and challenges. Mobility of students in the world, easy access to authentic sources and communication with native speakers through the Internet, the availability of various programs for the independent study of foreign languages helps students to cease to perceive the teacher as the only guarantor of the rules and source of knowledge. This makes foreign language teachers look for new methods and approaches to motivate students on the one hand and, on the other hand, not to lose their positions in the field of teaching foreign languages and in the labor market. Today teachers of foreign languages should be not only experts in technologies, but first of all - experts in mental habits.

scholarly journals A New Method in Attribution? Attempts of the Employment of Geometric Morphometrics in the Attribution of Late Archaic Attic Lekythoi

2019 ◽  
pp. 371-418
Author(s):  
Szilvia Joháczi
Keyword(s):  
Geometric Morphometrics ◽  
Ceramic Industry ◽  
Fine Arts ◽  
Classic Period ◽  
Vase Painting ◽  
Late Archaic ◽  
3D Reconstructions ◽  
Figure Technique ◽  
Early Classic Period ◽  
The One

In the Late Archaic - Early Classic period, the Attic ceramic industry was characterized by a kind of duality. On the one hand, the red-figure technique was flourishing, when Euphronios’, Douris’ or the Berlin Painter’s works represented the height of Greek vase painting. On the other hand, the market was also covered by large quantities of low-quality black-figure pottery. Not only in Athens, but even in the whole Ancient Mediterranean these mass-produced vessels emerge constantly, even from modern excavations. Therefore, in contrast to most vases of more talented painters they can be attached to an archaeological feature or layer. Due to their inadequate style, relatively few characteristics can be determined while looking at the painting. Thus, the manufacturing criteria, such as the details of the shapes, are more important in the attribution. In this paper, I study the late black-figure lekythoi of the Museum of Fine Arts in Budapest with the help of geometric morphometrics using 3D reconstructions.

scholarly journals Far-Eastern grey voles Alexandromys (Rodentia: Cricetidae) from Medvezhyi Klyk cave Late Pleistocene–Holocene deposits, Primorskii Kray, Russia

2019 ◽  
Vol 323 (3) ◽  
pp. 313-346 ◽  
Author(s):  
L.L. Voyta ◽  
F.N. Golenishchev ◽  
M.P. Tiunov
Keyword(s):  
Spatial Variation ◽  
Geometric Morphometrics ◽  
Late Pleistocene ◽  
Size Variation ◽  
Current Paper ◽  
Species Ranges ◽  
Broad Variety ◽  
Far Eastern

The current paper describes material from Medvezhyi Klyk Cave Late Pleistocene–Holocene deposits that represented mostly by isolated teeth. The morphology and size variation of the first lower teeth (n = 542) were studied. There are Alexandromysfortis, A. cf. maximowiczii, A. cf. oeconomus, A. cf. mongolicus determined in the material. We could not determine the taxa due to uncertainty in a spatial variation of the species ranges during Late Pleistocene and Holocene, a broad variety of the m1 anteroconid shape among medium-sized species of voles, and supposed presence “archaic” and “deviant” morphotypes of m1. Geometric morphometrics methods were shown the broad variety of the m1 anteroconid shape without strict species-relation, i.e., each tooth shows proper anteroconid shape, which can repeat within limits in populations in and among species.

Sign in / Sign up

Export Citation Format

Share Document