Morphology and life history of Amphora commutata (Bacillariophyta) I: the vegetative cell and phylogenetic position

Phycologia ◽  
2013 ◽  
Vol 52 (3) ◽  
pp. 225-238 ◽  
Author(s):  
Shinya Sato ◽  
Nagumo Tamotsu ◽  
David G. Mann
Keyword(s):  
Life History ◽  
Vegetative Cell ◽  
Phylogenetic Position ◽  
History Of

scholarly journals From chaos to order: the life history of Hannaea inaequidentata (Lagerstedt) Genkal and Kharitonov (Bacillariophyta), from initial cells to vegetative cells

PhytoKeys ◽  
2020 ◽  
Vol 162 ◽  
pp. 81-112
Author(s):  
Bing Liu ◽  
David M. Williams
Keyword(s):  
Life History ◽  
Vegetative Cell ◽  
Central Area ◽  
Cell Types ◽  
Initial Cell ◽  
Significant Length ◽  
History Of ◽  
Length Reduction ◽  
The Universe ◽  
Chaos Process

This study presents observations on three species of Hannaea and documents and illustrates the life history of H. inaequidentata. We have divided the life history of H. inaequidentata into the following four series of successive stages: auxospore, initial cell, pre-normal vegetative cell, and normal vegetative cell. The initial cell has a cylinder-like and a frequently twisted outline, a longitudinal perizonium wholly covering the valve surface, and a disc-shaped incunabular scale, but lacks any transverse perizonium bands. The pre-normal vegetative cell cannot form ribbon-like colonies, has a wide variety of irregular outlines and is composed of two cell types: one with its epivalve composed of either the initial epivalve or the initial hypovalve, its hypovalve being newly formed, the other with both its epivalve and hypovalve newly formed. The normal vegetative cell has a regular outline and exhibits a significant length reduction so that the largest valve is at least four times longer than the smallest. From initial cell to normal vegetative cell, the developmental sequence goes from ‘chaos to order’ as happens in many phenomena in the universe. The lack of transverse perizonium bands may be the cause of the initial ‘chaos’ process during its developing period from the initial cell to the normal vegetative cell. The development of frustule/valve shape, central area, sternum, virga, vimine, rimoportula and ocellulimbus etc. during the life circle is summarised. In the genus Hannaea, some taxa lack the strongly buttressed central area as in H. inaequidentata, which also has almost parallel valve margins.

Experimental life history of Echinostoma cinetorchis

1990 ◽  
Vol 28 (1) ◽  
pp. 39 ◽  
Author(s):  
S H Lee ◽  
J Y Chai ◽  
S T Hong ◽  
W M Sohn
Keyword(s):  
Life History ◽  
History Of

Queering Gender Identity Work: A Life History of a Black Transgender Woman

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Esethu Monakali
Keyword(s):  
Life History ◽  
Gender Identity ◽  
Public Spaces ◽  
Identity Work ◽  
Social Identities ◽  
Gender And Sexuality ◽  
Ongoing Effort ◽  
History Of ◽  
The Individual

This article offers an analysis of the identity work of a black transgender woman through life history research. Identity work pertains to the ongoing effort of authoring oneself and positions the individual as the agent; not a passive recipient of identity scripts. The findings draw from three life history interviews. Using thematic analysis, the following themes emerge: institutionalisation of gender norms; gender and sexuality unintelligibility; transitioning and passing; and lastly, gender expression and public spaces. The discussion follows from a poststructuralist conception of identity, which frames identity as fluid and as being continually established. The study contends that identity work is a complex and fragmented process, which is shaped by other social identities. To that end, the study also acknowledges the role of collective agency in shaping gender identity.

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