scholarly journals Crinoid encrustation of holocystitid diploporitan echinoderms: strongly asymmetrical Silurian dendritic attachment structures with palaeobiological implications

2021 ◽  
Vol 140 (1) ◽  
Author(s):  
James R. Thomka ◽  
Thomas E. Bantel ◽  
Carlton E. Brett
Keyword(s):  
Opposite Direction ◽  
Lateral Surface ◽  
Entire Length ◽  
Central Portion ◽  
Attachment Structures ◽  
Initial Settlement ◽  
Oral Area

AbstractArticulated thecae of the holocystitid diploporitan echinoderm Holocystites scutellatus from the middle Silurian (Wenlock: Sheinwoodian) Massie Formation of southeastern Indiana, USA, are encrusted by distinctive structures belonging to another echinoderm. A dendritic attachment structure consisting of multiple slender, branching radices, attributable to the camerate crinoid Eucalyptocrinites, is present on one side of each of the diploporitan thecae. However, the development of radices is remarkably asymmetrical, with all radices—including one more than 25 mm in length—being present exclusively on one side of the attachment structure. This reflects initial settlement by the encrusting crinoids near the oral or marginal regions rather than the central portion of the diploporitan thecae, which were on their sides; this essentially prohibited further outward growth of radices toward the oral area or edges, but allowed radices oriented in the opposite direction to extend over nearly the entire length of the lateral surface of the theca. Although crinoid encrustation of holocystitid diploporitan thecae is moderately common in the Massie Formation, no previously described specimens display such pronounced asymmetry with respect to radice development. More importantly, these specimens convincingly illustrate the degree to which Eucalyptocrinites attachment structure morphologies could be modified in response to local substrate variations; such skeletal modules were, indeed, highly dynamic, probably contributing to the success of taxa bearing such adaptable attachment structures.

Flagellar Attachment in Selected Trypanosomes

1973 ◽  
Vol 31 ◽  
pp. 496-497
Author(s):  
J. J. Paulin
Keyword(s):  
Cell Membrane ◽  
Lateral Surface ◽  
The Body ◽  
Flagellar Pocket ◽  
Integral Component ◽  
Free Flagellum ◽  
Flagellar Axoneme

Movement in epimastigote and trypomastigote stages of trypanosomes is accomplished by planar sinusoidal beating of the anteriorly directed flagellum and associated undulating membrane. The flagellum emerges from a bottle-shaped depression, the flagellar pocket, opening on the lateral surface of the cell. The limiting cell membrane envelopes not only the body of the trypanosome but is continuous with and insheathes the flagellar axoneme forming the undulating membrane. In some species a paraxial rod parallels the axoneme from its point of emergence at the flagellar pocket and is an integral component of the undulating membrane. A portion of the flagellum may extend beyond the anterior apex of the cell as a free flagellum; the length is variable in different species of trypanosomes.

Structure, compositon and function of the dermal-epidermal junction: Relevance in cutaneous disease and diagnosis

1989 ◽  
Vol 47 ◽  
pp. 868-869
Author(s):  
K. A. Holbrook
Keyword(s):  
Basement Membrane ◽  
Epidermolysis Bullosa ◽  
Normal Skin ◽  
Lamina Densa ◽  
Inherited Disorders ◽  
Ultrastructural Studies ◽  
Type Iv ◽  
Type Vii Collagen ◽  
Attachment Structures ◽  
Matrix Components

The dermal-epidermal junction (DEJ), or basement membrane rone, is the boundary between the epithelial and mesenchymal compartments of the skin; epidermal and fibroblastic cells in these two regions collaborate to synthesire its components. Ultrastructural studies (TEM and SEM) have defined a series of planes or layers (basal epidermal, lamina lucida, lamina densa, sublamina densa) and the morphology and density of attachment structures (hemidesmosomes, anchoring filaments, anchoring fibrils and anchoring plaques) in this region of normal skin. Change in structure of the DEJ provides information about the history of the tissue; reduplication of the lamina densa, for example, indicates a site of cell detachment or migration, or remodelling that accompanies repair of focal damage. In normal skin the structure of the DEJ is stable; in pathologic conditions it can be compromised by the congenital absence of certain structures or antigens (e.g., in the inherited disorders, epidermolysis bullosa [EB]) or by enzymatic degradation (e.g., in tumor invasion). Dissolution of the DEJ can also occur normally during the formation of epidermal appendages (e.g., hair follicles) and as melanocytes and Langerhans cells migrate into the epidermis during development.Biochemical and immunohisto/cytochemical studies have identified more than 20 molecules at the DEJ. These include well known matrix molecules (e.g., types IV and V collagen, laminin and fibronectin) and skin-specific antigens. The latter have been identified by autoantibodies or specific polyclonal or monoclonal antibodies raised against the skin, cultured cells and other epithelia. Some of the molecules of the DEJ are are present in basement membrane zones of many epithelia and thus are considered ubiquitous components (type IV, V, laminin, fibronectin, nidogen, entactin, HSPG, LDA-1, CSP [3B3]). All of them (that have been investigated in developing skin) appear ontogenetically as early as human embryonic tissue can be obtained and their expression is typically normal in patients with EB. The known properties of many of these molecules (particularly the matrix components) suggest functions they might impart to the DEJ: support of an epithelium (type IV collagen), regulation of permeability (heparan sulfate proteoglycan) or facilitation of cell attachment (fibronectin) and movement (laminin). Another group of matrix components and antigens of the DEJ includes molecules that are skin-specific or characteristic of stratified squamous epithelia (type VII collagen=LH 7:2 antigen, bullous pemphigoid antigen, AA3, GB3, KF-1,19-DEJ-1, epidermolysis bullosa acquisita antigen [EBA], AF-1 and AF-2, cicatricial pemphigoid antigen [CPA]) . These molecules are expressed in the DEJ later in development than the first group of molecules, in conjunction with the morphologic appearance of the structure they represent. Their appearance is also coordinated with specific developmental events (e.g., epidermal stratification) and the expression of molecules of differentiation in the epidermis and dermis. One or more of them is typically absent or reduced in expression in the skin of patients with heritable disorders affecting this region. There is no apparent correlation between the location of molecules in the DEJ and the stability of their expression.

Is Red Really Romantic?

2017 ◽  
Vol 48 (3) ◽  
pp. 174-183 ◽  
Author(s):  
Gabrielle K. Lehmann ◽  
Robert J. Calin-Jageman
Keyword(s):  
Opposite Direction ◽  
Positive Control ◽  
Weak Effect ◽  
Sample Sizes ◽  
Quality Controls

Abstract. Red has been reported to enhance attraction for women rating men ( Elliot et al., 2010 ) and men rating women ( Elliot & Niesta, 2008 ). We replicated one of these studies online and in-person. To ensure rigor, we obtained original materials, planned for informative sample sizes, pre-registered our study, used a positive control, and adopted quality controls. For men, we found a very weak effect in the predicted direction (d = 0.09, 95% CI [−0.17, 0.34], N = 242). For women, we found a very weak effect in the opposite direction (d = −0.09, 95% CI [−0.30, 0.12], N = 360). The original studies may have overestimated the red effect, our studies may be an underestimate, or there could be strong moderation of the effect of red on attraction.

Spontaneous self-affirmation before and during COVID-19: Associations with information-seeking, worry and adherence

2020 ◽  
Author(s):  
Tracy Epton ◽  
Chris Keyworth ◽  
Chris Armitage
Keyword(s):  
Older Adults ◽  
Opposite Direction ◽  
Information Seeking ◽  
Demographic Characteristics ◽  
Brief Interventions ◽  
Adaptive Behaviors ◽  
Uk Government ◽  
Nationally Representative

Objective: To assess the extent of spontaneous self-affirmation pre COVID-19 and during COVID-19 pandemic to identify for whom self-affirmation interventions might be helpful; and the extent to which spontaneous self-affirmation is associated with increased information-seeking, worry and adherence to UK government instructions. Methods: Two large nationally-representative surveys of UK adults were conducted via YouGov in March 2019 (pre COVID-19; N = 10421) and April 2020 (during COVID-19; N = 2252); both surveys measured demographic characteristics and spontaneous self-affirmation. The latter survey included measures of time spent accessing COVID-19 related news, worry about COVID-19 related news and degree of adherence to UK government instructions. Results: Spontaneous self-affirmation was lower before COVID-19 (44%) than it was during the pandemic (57%), although the pattern was in the opposite direction among older adults. Older adults were more likely to spontaneously self-affirm during COVID-19 than pre COVID-19. Greater spontaneous self-affirmation was associated with more time spent accessing news, and greater adherence to UK government instructions, but not media-related worry. Conclusions: The threat of COVID-19 may have triggered greater levels of spontaneous self-affirmation, which could give people the resources they needed to allow them to seek COVID-19-related news and adhere to UK government instructions. Groups lower in spontaneous self-affirmation, such as younger people could be targeted with brief interventions to promote self-affirmation and encourage performance of adaptive behaviors.

Genshin's Ojōyōshū and the Construction of Pure Land Discourse in Heian Japan

2017 ◽  
Author(s):  
Robert F. Rhodes
Keyword(s):  
Historical Background ◽  
Pivotal Role ◽  
Central Portion ◽  
Substantial Portion ◽  
Pure Land ◽  
Systematic Analysis ◽  
Heian Period ◽  
Pure Land Buddhism ◽  
Time Part ◽  
India And China

The Ōjōyōshū, written by the Heian period Tendai monk Genshin (942-1017), played a pivotal role in establishing Pure Land Buddhism in Japan. This book is a study of the central teachings of the Ōjōyōshū. Furthermore, in order to situate this text in its historical background, a substantial portion of the volume is taken up with discussions of the development of Pure Land Buddhism before Genshin’s time and to Genshin’s event-filled life. Part One provides a brief survey of Pure Land Buddhism in India and China and then treats how it developed in Japan before Genshin’s time. Part Two focuses on the main events of Genshin’s life. Part Three turns to two main issues taken up in the Ōjōyōshū: its Pure Land cosmology and its nenbutsu teaching. In his description of the Pure Land cosmology, Genshin describes, in often graphic detail, the suffering inherent in the six realms of transmigration, including hell, and urges his readers to seek birth in Amida Buddha’s Pure Land, a realm beyond suffering. Furthermore, in the central portion of the Ōjōyōshū, Genshin presents a systematic analysis of the nenbutsu, or the practice of focusing one’s mind on Amida, which is the central practice for attaining birth in the Pure Land.

A generic method of design of on-site stormwater detention storages

1995 ◽  
Vol 32 (1) ◽  
pp. 93-99 ◽  
Author(s):  
Donald Ian Phillips
Keyword(s):  
Design Theory ◽  
Drainage System ◽  
Entire Length ◽  
Community Assets ◽  
Drainage Design ◽  
Urban Consolidation ◽  
Universal Application ◽  
Method Of Design

On-site stormwater detention is widely used in Australia as a means of controlling the increased storm discharges from urban consolidation projects. However, unless the maximum permissible site discharge is correctly determined, the local piped drainage system may be overloaded. This paper presents a generic methodology that integrates detention storage behaviour with drainage design theory in such a manner as to protect the entire length of the downstream drainage system. Its generic nature facilitates its universal application to all systems, protecting these valuable community assets throughout their service lives.

Crystal Structure and Conformation of Ring A of 2β-Bromo-19β,28-epoxy-18α-oleanan-3-one

1993 ◽  
Vol 58 (11) ◽  
pp. 2737-2744 ◽  
Author(s):  
Jiří Novotný ◽  
Jaroslav Podlaha ◽  
Jiří Klinot
Keyword(s):  
Crystal Structure ◽  
Opposite Direction ◽  
Chair Conformation ◽  
Boat Conformation ◽  
Form Ring ◽  
Twist Boat

The crystal structure of β-bromo-19β,28-epoxy-18α-oleanan-3-one was elucidated. The crystal is orthorhombic, P212121, a = 9.686(1), b = 14.355(2), c = 19.687(4) Å, Z = 4, R = 0.042 for 2 410 observed reflections. Rings B, C, D and E adopt the chair conformation, the five membered ether cycle in ring E occurs in the envelope form. Ring A takes the twist-boat conformation turned towards the classical boat with C2 and C5 in the stem-stern position, in contrast to the conformation in solution, which is turned in the opposite direction towards the classical boat with C3 and C10 in the stem-stern positions.

Presocratic Theology

2009 ◽  
Author(s):  
T. M. Robinson
Keyword(s):  
Opposite Direction ◽  
Greek Thought ◽  
The World ◽  
Causal Sequence ◽  
The Universe

If in the context of early and classical Greek thought, the term “theology” is taken to mean “of God/gods/the gods and his/their putative relationship, causal and directive, to the world and its operations, and to ourselves within that world,” or something of that order, the first ascription of such a notion to a Presocratic philosopher is to be found in Aristotle's comment that “Thales thought that all things are full of gods”. The Presocratic period ends with no neat causal sequence. If one train of thinking was moving in the direction of a divinely guided, teleologically explicable universe, another was moving in exactly the opposite direction. For the atomists Democritus and Leucippus, the ever-changing universe is an infinity of space in which, across eternity, chance agglomerations of ever-moving atoms produce and will forever go on producing those contents of the universe that we call realities, from gazelles to galaxies.

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