Morphological diversity of the exine sculpture of some Frasnian spores from the northern Timan: Applications for taxonomy and significance for spore dispersal

2007 ◽  
Vol 41 (11) ◽  
pp. 1179-1189 ◽  
Author(s):  
A. L. Jurina ◽  
M. G. Raskatova
2019 ◽  
Vol 73 (3) ◽  
pp. 367
Author(s):  
Ross H. Miller ◽  
Robert G. Foottit ◽  
Eric Maw ◽  
Keith S. Pike

2017 ◽  
Author(s):  
Mathieu G.A. Lapotre ◽  
◽  
Ryan C. Ewing ◽  
Ryan C. Ewing ◽  
Michael P. Lamb ◽  
...  

Soft Matter ◽  
2021 ◽  
Author(s):  
Hakan Erdoğan

Different approaches are taken in order to examine the spontaneous arrangement processes of dipeptide structures. One of these approaches is to examine the effects of common cations on dipeptide structures'...


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 991
Author(s):  
Ana Maria Figueira Gomes ◽  
David Draper ◽  
Nascimento Nhantumbo ◽  
Rafael Massinga ◽  
José C. Ramalho ◽  
...  

Cowpea (Vigna unguiculata) is a neglected crop native to Africa, with an outstanding potential to contribute to the major challenges in food and nutrition security, as well as in agricultural sustainability. Two major issues regarding cowpea research have been highlighted in recent years—the establishment of core collections and the characterization of landraces—as crucial to the implementation of environmentally resilient and nutrition-sensitive production systems. In this work, we have collected, mapped, and characterized the morphological attributes of 61 cowpea genotypes, from 10 landraces spanning across six agro-ecological zones and three provinces in Mozambique. Our results reveal that local landraces retain a high level of morphological diversity without a specific geographical pattern, suggesting the existence of gene flow. Nevertheless, accessions from one landrace, i.e., Maringué, seem to be the most promising in terms of yield and nutrition-related parameters, and could therefore be integrated into the ongoing conservation and breeding efforts in the region towards the production of elite varieties of cowpea.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Léo Botton-Divet ◽  
John A. Nyakatura

Abstract Background Callitrichids comprise a diverse group of platyrrhine monkeys that are present across South and Central America. Their secondarily evolved small size and pointed claws allow them to cling to vertical trunks of a large diameter. Within callitrichids, lineages with a high affinity for vertical supports often engage in trunk-to-trunk leaping. This vertical clinging and leaping (VCL) differs from horizontal leaping (HL) in terms of the functional demands imposed on the musculoskeletal system, all the more so as HL often occurs on small compliant terminal branches. We used quantified shape descriptors (3D geometric morphometrics) and phylogenetically-informed analyses to investigate the evolution of the shape and size of the humerus and femur, and how this variation reflects locomotor behavior within Callitrichidae. Results The humerus of VCL-associated species has a narrower trochlea compared with HL species. It is hypothesized that this contributes to greater elbow mobility. The wider trochlea in HL species appears to correspondingly provide greater stability to the elbow joint. The femur in VCL species has a smaller head and laterally-oriented distal condyles, possibly to reduce stresses during clinging. Similarly, the expanded lesser trochanters visible in VCL species provide a greater lever for the leg retractors and are thus also interpreted as an adaptation to clinging. Evolutionary rate shifts to faster shape and size changes of humerus and femur occurred in the Leontocebus clade when a shift to slower rates occurred in the Saguinus clade. Conclusions Based on the study of evolutionary rate shifts, the transition to VCL behavior within callitrichids (specifically the Leontocebus clade) appears to have been an opportunity for radiation, rather than a specialization that imposed constraints on morphological diversity. The study of the evolution of callitrichids suffers from a lack of comparative analyses of limb mechanics during trunk-to-trunk leaping, and future work in this direction would be of great interest.


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