scholarly journals Estimating morphological diversity and tempo with discrete character-taxon matrices: implementation, challenges, progress, and future directions

2016 ◽  
Vol 118 (1) ◽  
pp. 131-151 ◽  
Author(s):  
Graeme T. Lloyd
Keyword(s):  
Morphological Diversity ◽  
Future Directions ◽  
Implementation Challenges ◽  
Discrete Character

Future Directions in Robotic Neurosurgery

2021 ◽  
Author(s):  
Christopher R Wagner ◽  
Timothy Phillips ◽  
Serge Roux ◽  
Joseph P Corrigan
Keyword(s):  
Machine Learning ◽  
Operating Room ◽  
Key Factors ◽  
Future Directions ◽  
Factors Affecting ◽  
Implementation Challenges ◽  
Image Guided ◽  
Robotic Neurosurgery ◽  
Specific Technology ◽  
Technology Trends

Abstract In this paper, we highlight promising technologies in each phase of a robotic neurosurgery operation, and identify key factors affecting how quickly these technologies will mature into products in the operating room. We focus on specific technology trends in image-guided cranial and spinal procedures, including advances in imaging, machine learning, robotics, and novel interfaces. For each technology, we discuss the required effort to overcome safety or implementation challenges, as well as identifying example regulatory approved products in related fields for comparison. The goal is to provide a roadmap for clinicians as to which robotic and automation technologies are in the developmental pipeline, and which ones are likely to impact their practice sooner, rather than later.

Morphological Diversity In The Evolutionary Radiation Of Paleozoic and Post-Paleozoic Crinoids

Paleobiology ◽  
1999 ◽  
Vol 25 (S2) ◽  
pp. 1-115 ◽  
Author(s):  
Mike Foote
Keyword(s):  
Data Analysis ◽  
Morphological Diversity ◽  
Ecological Strategies ◽  
Developmental Systems ◽  
Morphological Disparity ◽  
Morphological Diversification ◽  
Wide Range ◽  
Evolutionary Radiation ◽  
Discrete Character

The Paleozoic and post-Paleozoic radiations of crinoids present an opportunity to explore genomic and ecological explanations for patterns of morphologic diversification. Analysis of discrete-character data that cover the principal features of the crinoid skeleton shows that both Paleozoic and post-Paleozoic increases in morphological disparity were abrupt; this is consistent with rapid exploitation of open ecological opportunities in both cases. For the post-Paleozoic, this result is sensitive to some aspects of data analysis and sampling, so it cannot be regarded as unequivocal. The deceleration in morphological diversification within each radiation is consistent with an observed decline in rates of taxonomic origination as well as with the attainment of functional or structural limits. Despite these similarities in the two radiations, Paleozoic crinoids exploited a wider range of morphological designs than did their post-Paleozoic successors. Post-Paleozoic crinoids exploited a wide range of ecological strategies despite being stereotyped in many aspects of form. This difference between the radiations is consistent with an increase in the rigidity of genetic and developmental systems. The range of post-Paleozoic designs is not in essence a subset of the Paleozoic spectrum. The two radiations resulted in morphological distributions that are largely nonoverlapping, perhaps reflecting a different range of ecological strategies.

scholarly journals A combinatorial approach to angiosperm pollen morphology

2016 ◽  
Vol 283 (1843) ◽  
pp. 20162033 ◽  
Author(s):  
Luke Mander
Keyword(s):  
Pollen Morphology ◽  
Pollen Grains ◽  
Morphological Diversity ◽  
Taxonomic Diversity ◽  
Morphological Characters ◽  
Barro Colorado Island ◽  
Combinatorial Approach ◽  
Large Numbers ◽  
Discrete Character ◽  
Angiosperm Pollen

Angiosperms (flowering plants) are strikingly diverse. This is clearly expressed in the morphology of their pollen grains, which are characterized by enormous variety in their shape and patterning. In this paper, I approach angiosperm pollen morphology from the perspective of enumerative combinatorics. This involves generating angiosperm pollen morphotypes by algorithmically combining character states and enumerating the results of these combinations. I use this approach to generate 3 643 200 pollen morphotypes, which I visualize using a parallel-coordinates plot. This represents a raw morphospace. To compare real-world and theoretical morphologies, I map the pollen of 1008 species of Neotropical angiosperms growing on Barro Colorado Island (BCI), Panama, onto this raw morphospace. This highlights that, in addition to their well-documented taxonomic diversity, Neotropical rainforests also represent an enormous reservoir of morphological diversity. Angiosperm pollen morphospace at BCI has been filled mostly by pollen morphotypes that are unique to single plant species. Repetition of pollen morphotypes among higher taxa at BCI reflects both constraint and convergence. This combinatorial approach to morphology addresses the complexity that results from large numbers of discrete character combinations and could be employed in any situation where organismal form can be captured by discrete morphological characters.

scholarly journals Inference of DNA methylation patterns in molluscs

2021 ◽  
Vol 376 (1825) ◽  
Author(s):  
Lisa Männer ◽  
Tilman Schell ◽  
Panagiotis Provataris ◽  
Martin Haase ◽  
Carola Greve
Keyword(s):  
Dna Methylation ◽  
De Novo ◽  
Morphological Diversity ◽  
Dna Methyltransferases ◽  
Animal Kingdom ◽  
Future Directions ◽  
Protein Coding ◽  
General Picture ◽  
Methylation Patterns ◽  
De Novo Methylation

Mollusca are the second largest and arguably most diverse phylum of the animal kingdom. This is in sharp contrast to our very limited knowledge concerning epigenetic mechanisms including DNA methylation in this invertebrate group. Here, we inferred DNA methylation patterns by analysing the normalized dinucleotide CG content in protein-coding sequences and identified DNA methyltransferases (DNMT1 and 3) in published transcriptomes and genomes of 140 species across all eight classes of molluscs. Given the evolutionary age and morphological diversity of molluscs, we expected to find evidence for diverse methylation patterns. Our inferences suggest that molluscs possess substantial levels of DNA methylation in gene bodies as a rule. Yet, we found deviations from this general picture with regard to (i) the CpG observed/expected distributions indicating a reduction in DNA methylation in certain groups and (ii) the completeness of the DNMT toolkit. Reductions were evident in Caudofoveata, Solenogastres, Polyplacophora, Monoplacophora, as well as Scaphopoda. Heterobranchia and Oegopsida were remarkable as they lacked DNMT3, usually responsible for de novo methylation, yet showed signs of DNA methylation. Our survey may serve as guidance for direct empirical analyses of DNA methylation in molluscs. This article is part of the Theo Murphy meeting issue ‘Molluscan genomics: broad insights and future directions for a neglected phylum’.

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