scholarly journals Sexual size and shape dimorphism in Brachydesmus troglobius Daday, 1889 (Diplopoda, Polydesmida)

ZooKeys ◽  
2020 ◽  
Vol 930 ◽  
pp. 75-88
Author(s):  
Vukica Vujić ◽  
Luka Lučić ◽  
Sofija Pavković-Lučić ◽  
Bojan Ilić ◽  
Zvezdana Jovanović ◽  
...  
Keyword(s):  
Geometric Morphometrics ◽  
Morphological Trait ◽  
Trait Variation ◽  
Size Dimorphism ◽  
Size And Shape ◽  
Shape And Size

Until now, morphological trait variation has been investigated in several millipede species using geometric morphometrics. The present study is the first attempt to explore sexual shape and size dimorphism (SShD and SSD) of morphological structures in Polydesmida. We here analyse antennal, head, and leg SShD and SSD in Brachydesmus troglobius Daday, 1889. Our results show that SSD exists in all of the analysed structures, while SShD is present only in the legs. In comparison with females, males possess longer and wider legs, as well as longer antennae and a shorter head. Contrary to previous findings in some Julida, in B. troglobiusSSD of the antennae and legs varies more than SShD in these morphological structures.

scholarly journals Morphological variation ofAphidius erviHaliday (Hymenoptera: Braconidae) associated with different aphid hosts

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3559 ◽  
Author(s):  
Cinthya M. Villegas ◽  
Vladimir Žikić ◽  
Saša S. Stanković ◽  
Sebastián A. Ortiz-Martínez ◽  
Ainara Peñalver-Cruz ◽  
...  
Keyword(s):  
Biological Control ◽  
Geometric Morphometrics ◽  
Acyrthosiphon Pisum ◽  
Biological Control Agent ◽  
Feeding Habits ◽  
Aphidius Ervi ◽  
Wing Size ◽  
Size And Shape ◽  
Aphid Host ◽  
Shape And Size

BackgroundParasitoids are frequently used in biological control due to the fact that they are considered host specific and highly efficient at attacking their hosts. As they spend a significant part of their life cycle within their hosts, feeding habits and life history of their host can promote specialization via host-race formation (sequential radiation). The specialized host races from different hosts can vary morphologically, behaviorally and genetically. However, these variations are sometimes inconspicuous and require more powerful tools in order to detect variation such as geometric morphometrics analysis.MethodsWe examinedAphidius ervi, an important introduced biological control agent in Chile associated with a great number of aphid species, which are exploiting different plant hosts and habitats. Several combinations (biotypes) of parasitoids with various aphid/host plant combinations were analyzed in order to obtain measures of forewing shape and size. To show the differences among defined biotypes, we chose 13 specific landmarks on each individual parasitoid wing. The analysis of allometric variation calculated in wing shape and size over centroid size (CS), revealed the allometric changes among biotypes collected from different hosts. To show all differences in shape of forewings, we made seven biotype pairs using an outline-based geometric morphometrics comparison.ResultsThe biotypeA. pis_pea(Acyrthosiphon pisumon pea) was the extreme wing size in this study compared to the other analyzed biotypes. Aphid hosts have a significant influence in the morphological differentiation of the parasitoid forewing, splitting biotypes in two groups. The first group consisted of biotypes connected withAcyrthosiphon pisumon legumes, while the second group is composed of biotypes connected with aphids attacking cereals, with the exception of theR. pad_wheat(Rhopalosiphum padion wheat) biotype. There was no significant effect of plant species on parasitoid wing size and shape.DiscussionAlthough previous studies have suggested that the genotype of parasitoids is of greater significance for the morphological variations of size and shape of wings, this study indicates that the aphid host on whichA. ervidevelops is the main factor to alter the structure of parasitoid forewings. Bigger aphid hosts implied longer and broader forewings ofA. ervi.

scholarly journals Sexual dimorphism in cranial shape and size in geomyoid rodents: multivariate and evolutionary perspectives

2021 ◽  
Author(s):  
Jonathan J M Calede ◽  
Andrew Brown
Keyword(s):  
Sexual Dimorphism ◽  
Arid Environments ◽  
Evolutionary Patterns ◽  
Rensch’S Rule ◽  
Size Dimorphism ◽  
Size And Shape ◽  
Rensch's Rule ◽  
Cranial Measurements ◽  
Patterns And Processes ◽  
Shape And Size

Abstract Geomyoid rodents provide a great study system for the analysis of sexual dimorphism. They are polygynic and many inhabit harsh arid environments thought to promote sexual dimorphism. In fact, there has been extensive work published on the sexual size dimorphism of individual populations and species within this rodent clade. However, little work has been undertaken to assess the evolutionary patterns and processes associated with this sexual dimorphism. We use multivariate analyses of cranial measurements in a phylogenetic framework to determine the distribution of size and shape dimorphism among geomyoids and test for Rensch’s rule. Our results suggest that sexual dimorphism is more common in geomyids than heteromyids, but it is not in fact universal. There is evidence for variation in sexual dimorphism across populations. Additionally, in many taxa, geographic variation appears to overwhelm existing sexual dimorphism. We find support for the repeated independent evolution of shape and size dimorphism across geomyoid taxa, but we do not find support for an association between size and shape dimorphism. There is no evidence for Rensch’s rule in geomyoids, whether at the superfamily or family level. Together, our findings suggest that there is no single explanation for the evolution of sexual dimorphism in geomyoids and that, instead, it is the product of numerous evolutionary events. Future studies incorporating phylogenetic relationships will be necessary to paint a more complete picture of the evolution of sexual dimorphism in geomyoids.

scholarly journals The fruit metric trait characterization of scarlet eggplant using the high-throughput tomato analyzer software

2021 ◽  
Vol 66 (2) ◽  
pp. 139-154
Author(s):  
Olawale Adeniji ◽  
Modinat Adekoya ◽  
Peter Jonah ◽  
Innocent Iseghohi ◽  
Charity Aremu
Keyword(s):  
Genotypic Variation ◽  
Fruit Size ◽  
Fruit Shape ◽  
Trait Variation ◽  
Yield Improvement ◽  
Fruit Size And Shape ◽  
Metric Traits ◽  
Shape And Size ◽  
Tomato Analyzer

Scarlet eggplant (Solanum aethiopicum [L.]) is an indigenous, underutilized fruit vegetable in Africa. Preference for fruit shape and size is high among growers and consumers. Fruit metric traits are important for yield improvement. Fruit metric descriptors are important contributors to variation, phenotypic and genotypic variation, and heritability. However, the measurement of these traits is cumbersome and subjective. Forty-three accessions were evaluated in 2016 and 2017. At maturity, 5 fruits were randomly harvested from each accession, digitalized and processed using the Tomato Analyzer software. Sixteen fruit metric traits were automatically generated and submitted for analysis of variance and multivariate analysis. The accessions differed over fruit size and shape due to genetic make-up. Fruit metric trait variation among S. aethiopicum groups was less influenced by the environment. The cv. Gilo group has oblong fruits, the cv. Shum group fruits are circular and ovoid; the cv. Kumba group fruits are less circular, lobed and flattened. AE/113 (C3), FUO 1 (C1) and FUO 5 (C2) Gilo groups are promising for fruit size. There were phenotypic plasticity and overlapping for fruit metric traits between the Gilo and Shum groups due to a common genome. The Tomato Analyzer software was able to discriminate accessions based on fruit phenomic traits, and the information could be used to establish commonalities between groups.

Cooling Rates of Brake Drums and Discs

1965 ◽  
Vol 180 (1) ◽  
pp. 191-205 ◽  
Author(s):  
T.P. Newcomb ◽  
N. Millner
Keyword(s):  
Cooling Rate ◽  
Air Flow ◽  
Vehicle Speed ◽  
Uniform Temperature ◽  
Cooling Rates ◽  
Size And Shape ◽  
Slip Ring ◽  
Disc Brakes ◽  
Shape And Size ◽  
Time Plot

An investigation has been made of the rates of cooling of vehicle brake drums and discs. Thermocouples were inserted in the drums and discs and in the wheel hubs and their outputs fed via slip ring units to meters mounted inside the vehicle. The drums or discs were heated to a uniform temperature of 300°-400°C by drag braking and the rate at which they cooled measured while the vehicle was driven at constant speed. Measurements were made at various speeds in the range 0 to 90 mile/h. From the log (temperature) against time plot a cooling coefficient bv was determined. It is shown that at a vehicle speed v the quantity bv can be expressed in the form bv = b0 +Kv0·8 where b0 represents the loss of heat to the hub and K is a constant depending on the size and shape of the drum or disc. Values of these constants have been determined on a variety of cars having discs and drums varying from 7 in to 11 in diameter and on a lorry fitted with 16·75 in diameter drums. Cooling rates are shown to depend on shape and size of the disc or drum. Results show that the cooling rates of front brakes are about 20 per cent higher than the rear brakes and that front discs cool about 25 per cent more quickly than the corresponding drum size recommended for the same vehicle. The cooling rate of front discs did not change when wire wheels were fitted instead of solid wheels. Ventilated discs and solid discs were also compared. The effect of fitting dust shields on disc brakes is shown to reduce the cooling rates by about 30 per cent. The effect of otherwise disturbing the air flow was studied.

Synthesis and characterization of size- and shape-controlled silver nanoparticles

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Suparna Mukherji ◽  
Sharda Bharti ◽  
Gauri Shukla ◽  
Soumyo Mukherji
Keyword(s):  
Silver Nanoparticles ◽  
Nucleation And Growth ◽  
Detailed Review ◽  
Size And Shape ◽  
Physical Chemical ◽  
Application Potential ◽  
Shape Controlled ◽  
Synthesis Routes ◽  
Shape And Size

Abstract Silver nanoparticles (AgNPs) have application potential in diverse areas ranging from wound healing to catalysis and sensing. The possibility for optimizing the physical, chemical and optical properties for an application by tailoring the shape and size of silver nanoparticles has motived much research on methods for synthesis of size- and shape-controlled AgNPs. The shape and size of AgNPs are reported to vary depending on choice of the Ag precursor salt, reducing agent, stabilizing agent and on the synthesis technique used. This chapter provides a detailed review on various synthesis approaches that may be used for synthesis of AgNPs of desired size and shape. Silver nanoparticles may be synthesized using diverse routes, including, physical, chemical, photochemical, biological and microwave -based techniques. Synthesis of AgNPs of diverse shapes, such as, nanospheres, nanorods, nanobars, nanoprisms, decahedral nanoparticles and triangular bipyramids is also discussed for chemical-, photochemical- and microwave-based synthesis routes. The choice of chemicals used for reduction and stabilization of nanoparticles is found to influence their shape and size significantly. A discussion on the mechanism of synthesis of AgNPs through nucleation and growth processes is discussed for AgNPs of varying shape and sizes so as to provide an insight on the various synthesis routes. Techniques, such as, electron microscopy, spectroscopy, and crystallography that can be used for characterizing the AgNPs formed in terms of their shape, sizes, crystal structure and chemical composition are also discussed in this chapter. Graphical Abstract:

Morphological trait variation and relationships of Afzelia africana Sm. caused by climatic conditions and anthropogenic disturbance in Benin (West Africa)

2019 ◽  
Vol 66 (5) ◽  
pp. 1091-1105 ◽  
Author(s):  
Thierry D. Houehanou ◽  
Kathleen Prinz ◽  
Frank Hellwig ◽  
Achille E. Assogbadjo ◽  
Jens Gebauer ◽  
...  
Keyword(s):  
West Africa ◽  
Anthropogenic Disturbance ◽  
Climatic Conditions ◽  
Morphological Trait ◽  
Trait Variation ◽  
Afzelia Africana

scholarly journals Quantifying Wing Shape and Size of Saturniid Moths with Geometric Morphometrics

2016 ◽  
Vol 70 (2) ◽  
pp. 99-107 ◽  
Author(s):  
Minjia Zhong ◽  
Geena M. Hill ◽  
Juan P. Gomez ◽  
David Plotkin ◽  
Jesse R. Barber ◽  
...  
Keyword(s):  
Geometric Morphometrics ◽  
Wing Shape ◽  
Shape And Size

Brownian motions on shape and size-and-shape spaces

1994 ◽  
Vol 31 (1) ◽  
pp. 101-113 ◽  
Author(s):  
Huiling Le
Keyword(s):  
Dual Problem ◽  
Heat Kernels ◽  
Brownian Motions ◽  
Shape Spaces ◽  
Size And Shape ◽  
Shape And Size

The diffusions on the shape and size-and-shape spaces induced by brownian motions on the pre-size-and-shape spaces have been investigated in several papers (cf.). We here address the dual problem: the character of the diffusions on the pre-shape and pre-size-and-shape spaces which induce brownian motions on the shape and size-and-shape spaces. In particular we show that the shape and size-and-shape spaces for k labelled points in ℝm are stochastically complete if k > m and obtain the heat kernels of certain diffusions which induce brownian motions on the size-and-shape spaces.

scholarly journals Variation in pelvic shape and size in Eastern European males: a computed tomography comparative study

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6433 ◽  
Author(s):  
Bartosz Musielak ◽  
Anna Maria Kubicka ◽  
Michał Rychlik ◽  
Jarosław Czubak ◽  
Adam Czwojdziński ◽  
...  
Keyword(s):  
Geometric Morphometrics ◽  
Body Mass ◽  
Three Dimensional ◽  
Opening Angle ◽  
Control Group ◽  
Human Society ◽  
Eastern European ◽  
Adult Males ◽  
Pelvic Shape ◽  
Shape And Size

Background The significantly accelerated development of human society in the last millennium has brought about changes in human behavior and body mass that may have influenced human bone morphology. Our objective was to analyze the variation in pelvic shape and size in males from modern and medieval populations. Methods We obtained 22 pelvic girdles of adult males from a medieval cemetery located in Cedynia, Poland. The control group comprised 31 contemporary male pelves from individuals inhabiting the same region. The analyzed parameters were: interspinous distance (ISD), intercristal distance (ICD), intertuberous distance (ITD), anatomic conjugate of the pelvis, height of the pelvis (HP), iliac opening angle (IOA), iliac tilt angle (ITA), and ISD/ITD/HP ratio. Geometric morphometrics was used to analyze differences in shape in the pelves. All analyses were carried out on three-dimensional CT reconstructions of pelves. Results ISD, ICD, and IOA were significantly greater in modern pelves than in those from Cedynia, but no significant differences were seen between the two groups in ITD, anatomical conjugate, HP, or ITA. ISD/ITD/HP ratios were significantly lower in the Cedynia group. Geometric morphometrics revealed significant differences in pelvic shape between the analyzed groups. Discussion The pelves of modern males are larger, wider, and flatter than those of medieval males. Changes in the set of daily activities that produce mechanical loading and estimated body mass may constitute the main factors explaining pelvic variability. However, differences in ontogenesis should also be taken into consideration, especially since growth in past populations is often found to be reduced relative to modern populations.

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