scholarly journals Beyond Agricola: The Multiple Origins of European Knowledge in Adam Schall von Bell’s Chinese Mining and Metallurgy Handbook <italic>Kunyu Gezhi</italic> (1640)

2021 ◽  
Vol 5 (1) ◽  
pp. 58-89
Author(s):  
Alexander JOST
Keyword(s):  
Multiple Origins

Comparative Analysis of Genetic and Morphological Variation within the Platanthera hyperborea Complex (Orchidaceae)

2020 ◽  
Vol 45 (4) ◽  
pp. 767-778
Author(s):  
Eranga Wettewa ◽  
Nick Bailey ◽  
Lisa E. Wallace
Keyword(s):  
North America ◽  
Diploid Species ◽  
Morphological Characters ◽  
Evolutionary Patterns ◽  
Founding Population ◽  
Multiple Origins ◽  
Geographic Structure ◽  
Species Complexes ◽  
Nuclear Its ◽  
Cryptic Taxa

Abstract—Species complexes present considerable problems for a working taxonomy due to the presence of intraspecific variation, hybridization, polyploidy, and phenotypic plasticity. Understanding evolutionary patterns using molecular markers can allow for a more thorough assessment of evolutionary lineages than traditional morphological markers. In this study, we evaluated genetic diversity and phylogenetic patterns among taxa of the Platanthera hyperborea (Orchidaceae) complex, which includes diploid (Platanthera aquilonis) and polyploid (Platanthera hyperborea, P. huronensis, and P. convallariifolia) taxa spanning North America, Greenland, Iceland, and Asia. We found that three floral morphological characters overlap among the polyploid taxa, but the diploid species has smaller flowers. DNA sequence variation in a plastid (rpL16 intron) and a nuclear (ITS) marker indicated that at least three diploid species have contributed to the genomes of the polyploid taxa, suggesting all are of allopolyploid origin. Platanthera convallariifolia is most like P. dilatata and P. stricta, whereas P. huronensis and P. hyperborea appear to have originated from crosses of P. dilatata and P. aquilonis. Platanthera huronensis, which is found across North America, has multiple origins and reciprocal maternal parentage from the diploid species. By contrast, P. hyperborea, restricted to Greenland and Iceland, appears to have originated from a small founding population of hybrids in which P. dilatata was the maternal parent. Geographic structure was found among polyploid forms in North America. The area of Manitoba, Canada appears to be a contact zone among geographically diverse forms from eastern and western North America. Given the geographic and genetic variation found, we recommend continued recognition of four green-flowered species within this complex, but caution that there may be additional cryptic taxa within North America.

scholarly journals Quality assessment and antioxidant activities of the blossoms of Inula nervosa Wall

2020 ◽  
Author(s):  
Li-xia Hu ◽  
Mei-feng Luo ◽  
Wen-jing Guo ◽  
Xiao He ◽  
Jun Zhou ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Quantitative Data ◽  
Antioxidant Activities ◽  
Quality Criteria ◽  
Chemical Compounds ◽  
Traditional Chinese Medicines ◽  
Chinese Medicines ◽  
Chemical Profiling ◽  
Multiple Origins ◽  
The Difference

Abstract Background Currently, although Inula nervosa Wall is well investigated, little is understood about blossoms of Inula nervosa Wall (BINW). Objective In this work, we systematically investigated the antioxidant activity of the extract from BINW by various standard assays including DPPH free radical ability, ABTS• +, and FRAP. Methods Chemical compounds are tentatively identified through an UHPLC-QTOF-MS system. Furthermore, the contents of nine compounds were detected with UHPLC method coupled with PDA. By carefully analyzing the quantitative data via clusters analysis and PCA. Results 46 compounds are tentatively identified and our results showed that 9 compound samples in 21 batches of BINW collected from different areas could be differentiated and analyzed by a heatmap visualization. In addition, the contents of nine compounds (flavonoids, phenolic acids) exhibited a total of higher amounts and better antioxidant activities from Yunnan than those from other three origins. Conclusions Our study not only developed a powerful platform to explain the difference traditional Chinese medicines (TCMs) species that in closely related through the chemometric and chemical profiling, but also presented a useful method to establish quality criteria of BINW with multiple origins. Highlights To detailly characterize the BINW, we not only performed DPPH, FRAP and ABTS assays to investigate its antioxidant activity, but also established UHPLC-QTOF-MS/MS and UHPLC-PDA based methods to comprehensively identify and qualitatively analyze its components.

scholarly journals Molecular evolution of HoxA13 and the multiple origins of limbless morphologies in amphibians and reptiles

2015 ◽  
Vol 38 (3) ◽  
pp. 255-262 ◽  
Author(s):  
Marina E. Singarete ◽  
Mariana B. Grizante ◽  
Sarah R. Milograna ◽  
Mariana F. Nery ◽  
Koryu Kin ◽  
...  
Keyword(s):  
Molecular Evolution ◽  
Multiple Origins

scholarly journals Multiple origins of transcription for the human placental lactogen genes.

1984 ◽  
Vol 259 (23) ◽  
pp. 14642-14646 ◽  
Author(s):  
C S Selvanayagam ◽  
S Y Tsai ◽  
M J Tsai ◽  
P Selvanayagam ◽  
G F Saunders
Keyword(s):  
Placental Lactogen ◽  
Human Placental Lactogen ◽  
Multiple Origins

scholarly journals Thermal laser ablation with tunable lesion size reveals multiple origins of seizure-like convulsions in Caenorhabditis elegans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anthony D. Fouad ◽  
Alice Liu ◽  
Angelica Du ◽  
Priya D. Bhirgoo ◽  
Christopher Fang-Yen
Keyword(s):  
Laser Ablation ◽  
Ventral Nerve Cord ◽  
High Spatial Resolution ◽  
Laser System ◽  
Laser Pulses ◽  
Lesion Size ◽  
Single Neurons ◽  
C Elegans ◽  
Multiple Origins ◽  
Important Means

AbstractLaser microsurgery has long been an important means of assessing the functions of specific cells and tissues. Most laser ablation systems use short, highly focused laser pulses to create plasma-mediated lesions with dimensions on the order of the wavelength of light. While the small size of the lesion enables ablation with high spatial resolution, it also makes it difficult to ablate larger structures. We developed an infrared laser ablation system capable of thermally lesioning tissues with spot sizes tunable by the duration and amplitude of laser pulses. We used our laser system in the roundworm C. elegans to kill single neurons and to sever the dorsal and ventral nerve cords, structures that are difficult to lesion using a plasma-based ablation system. We used these ablations to investigate the source of convulsions in a gain-of-function mutant for the acetylcholine receptor ACR-2. Severing the ventral nerve cord caused convulsions to occur independently anterior and posterior to the lesion, suggesting that convulsions can arise independently from distinct subsets of the motor circuit.

Sign in / Sign up

Export Citation Format

Share Document