Empirical and theoretical study of atelostomate (Echinoidea, Echinodermata) plate architecture: using graph analysis to reveal structural constraints

Paleobiology ◽  
2015 ◽  
Vol 41 (3) ◽  
pp. 436-459 ◽  
Author(s):  
Thomas Saucède ◽  
Rémi Laffont ◽  
Catherine Labruère ◽  
Ahmed Jebrane ◽  
Eric François ◽  
...  
Keyword(s):  
Structural Constraints ◽  
Discrete Elements ◽  
Morphological Disparity ◽  
Apical Plate ◽  
Morphological Organization ◽  
Connectivity Patterns ◽  
Recent Species ◽  
Evolutionary Radiations ◽  
Random Patterns ◽  
Clear Increase

AbstractDescribing patterns of connectivity among organs is essential for identifying anatomical homologies among taxa. It is also critical for revealing morphogenetic processes and the associated constraints that control the morphological diversification of clades. This is particularly relevant for studies of organisms with skeletons made of discrete elements such as arthropods, vertebrates, and echinoderms. Nonetheless, relatively few studies devoted to morphological disparity have considered connectivity patterns as a level of morphological organization or developed comparative frameworks with proper tools. Here, we analyze connectivity patterns among apical plates in Atelostomata, the most diversified clade among irregular echinoids. The clade comprises approximately 1600 fossil and Recent species (e.g., 25% of post-Paleozoic species of echinoids) and shows high levels of morphological disparity. Plate connectivity patterns were analyzed using tools and statistics of graph theory. To describe and explore the diversity of connectivity patterns among plates, we symbolized each pattern as a graph in which plates are coded as nodes that are connected pairwise by edges. We then generated a comparative framework as a morphospace of connections, in which the disparity of plate patterns observed in nature was mapped and analyzed. Main results show that apical plate patterns are both highly disparate between and within atelostomate groups and limited in number; overall, they also constitute small, compact, and simple structures compared to possible random patterns. Main traits of the evolution of apical plate patterns reveal the existence of strong morphogenetic constraints that are phylogenetically determined. In contrast, evolutionary radiations within atelostomates were accompanied by a clear increase in disparity, suggesting a release of some constraints at the origin of clades.

When adaptive radiations collide: Different evolutionary trajectories between and within island and mainland lizard clades

2021 ◽  
Vol 118 (42) ◽  
pp. e2024451118 ◽  
Author(s):  
Austin H. Patton ◽  
Luke J. Harmon ◽  
María del Rosario Castañeda ◽  
Hannah K. Frank ◽  
Colin M. Donihue ◽  
...  
Keyword(s):  
South America ◽  
Hawaiian Islands ◽  
Morphological Diversity ◽  
Oceanic Islands ◽  
Morphological Disparity ◽  
Evolutionary Diversification ◽  
Evolutionary Trajectories ◽  
Adaptive Radiations ◽  
Evolutionary Radiations ◽  
The Caribbean

Oceanic islands are known as test tubes of evolution. Isolated and colonized by relatively few species, islands are home to many of nature’s most renowned radiations from the finches of the Galápagos to the silverswords of the Hawaiian Islands. Despite the evolutionary exuberance of insular life, island occupation has long been thought to be irreversible. In particular, the presumed much tougher competitive and predatory milieu in continental settings prevents colonization, much less evolutionary diversification, from islands back to mainlands. To test these predictions, we examined the ecological and morphological diversity of neotropical Anolis lizards, which originated in South America, colonized and radiated on various islands in the Caribbean, and then returned and diversified on the mainland. We focus in particular on what happens when mainland and island evolutionary radiations collide. We show that extensive continental radiations can result from island ancestors and that the incumbent and invading mainland clades achieve their ecological and morphological disparity in very different ways. Moreover, we show that when a mainland radiation derived from island ancestors comes into contact with an incumbent mainland radiation the ensuing interactions favor the island-derived clade.

Cytoplasmic Organization in the Receptor Cells of the Crista Ampullaris

1972 ◽  
Vol 30 ◽  
pp. 60-61 ◽  
Author(s):  
Robert F. Dunn
Keyword(s):  
Fine Particles ◽  
Apical Cell ◽  
Apical Region ◽  
Receptor Cells ◽  
Cuticular Plate ◽  
Morphological Organization ◽  
Crista Ampullaris ◽  
Cytoplasmic Organization ◽  
High Degree ◽  
General Appearance

Receptor cells of the cristae in the vestibular labyrinth of the bullfrog, Rana catesbiana, show a high degree of morphological organization. Four specialized regions may be distinguished: the apical region, the supranuclear region, the paranuclear region, and the basilar region.The apical region includes a single kinocilium, approximately 40 stereocilia, and many small microvilli all projecting from the apical cell surface into the lumen of the ampulla. A cuticular plate, located at the base of the stereocilia, contains filamentous attachments of the stereocilia, and has the general appearance of a homogeneous aggregation of fine particles (Fig. 1). An accumulation of mitochondria is located within the cytoplasm basal to the cuticular plate.

STRUCTURAL CONSTRAINTS ON COGNITIVE THEORY

1980 ◽  
Vol 25 (2) ◽  
pp. 203-204
Author(s):  
JOSEPH M. SCANDURA
Keyword(s):  
Cognitive Theory ◽  
Structural Constraints

Anticipatory memory for regular and random patterns.

2020 ◽  
Vol 46 (9) ◽  
pp. 965-978 ◽  
Author(s):  
Irem Yildirim ◽  
Helene Intraub
Keyword(s):  
Random Patterns

FEATURES OF FORMATION OF THE MAIN SYSTEMS AND ORGANS IN EARLY LARVAE OF MULLETS (LIZA AURATA, RISSO, 1810)

2017 ◽  
pp. 98-106
Author(s):  
Dariya Aleksandrovna Gavrilova ◽  
Maria Pavlovna Grushko
Keyword(s):  
Nervous System ◽  
Sample Selection ◽  
Early Ontogeny ◽  
Basal Cells ◽  
The Caspian Sea ◽  
Liza Aurata ◽  
Morphological Organization ◽  
Organ Systems ◽  
Major Organ ◽  
Well Differentiated

The aim of this work was to study peculiarities of mullet morphological organization during early ontogeny. Sample selection was made on board Caspian research and development Institute of Fisheries’ research vessel in period from June to September, 2015 in Russian waters of the Caspian Sea. Larvae aged 10 days could be characterized by heterochrony in the development of major organ systems. Nervous system and sense organs were well developed. The eyeball had all membranes well-differentiated, in the retina all the layers were formed. The olfactory fossae had cells of 3 types: olfactory receptor cells, supporting cells and basal cells. There was observed intensive formation of respiratory, cardiovascular, excretory and digestive systems. The early development of the nervous system and sensory organs of the larvae indicated adaptation of mullet to active life.

Information-seeking to Support Personal and Community Wellbeing: Report of a study of New Zealand Men Using Focus Groups

2016 ◽  
Author(s):  
Peta Wellstead
Keyword(s):  
New Zealand ◽  
Focus Groups ◽  
Support Services ◽  
Information Seeking ◽  
Service Providers ◽  
Structural Constraints ◽  
Health And Wellbeing ◽  
Study Results ◽  
Groupes De Discussion

This paper reports part of an ongoing study exploring the information behaviour of New Zealand men during periods of diminished health and wellbeing. Focus groups were used for this iteration of the study. Results indicate that New Zealand men face both personal and structural constraints to their information-seeking during periods when their health and wellbeing may be compromised. This study highlights that service providers need to develop more effective information delivery mechanisms and support services for men. These services need to be appealing to men and reflect men’s information seeking preferences. The role of LIS professionals in supporting this endeavour is discussed. Cet article présente une étude en cours explorant le comportement informationnel d’ hommes néo-zélandais durant des périodes où leur état de santé et de bien-être est amoindri. Des groupes de discussion ont été utilisés pour cette itération de l'étude. Les résultats indiquent que les hommes en Nouvelle-Zélande font face à des contraintes à la fois  personnelles et structurelles dans leur recherche d'information pendant les périodes où leur santé et leur bien-être peuvent être affaiblis. Cette étude met en évidence le besoin pour les fournisseurs de services de développer des mécanismes de diffusion de l'information plus efficaces et des services de soutien pour les hommes. Ces services doivent être attrayants et refléter les préférences des hommes dans leurs recherches d’information. Le rôle des professionnels de l'information dans le soutien à cette entreprise est discuté.

COMPARISON OF THE QUALITY OF LIFE OF PATIENTS IN THE LOCALY ADVANCED BREAST CANCER FORMS AFTER SYSTEM AND INTRALYMPHATIC POLYCHEMOTHERAPY

2018 ◽  
Vol 4 ◽  
pp. 3-13
Author(s):  
Yuriy Dumanskiy ◽  
Oleksandr Bondar ◽  
Oleksandr Tkachenko ◽  
Evhenii Stoliachuk ◽  
Vasilii Ermakov
Keyword(s):  
Breast Cancer ◽  
Quality Of Life ◽  
Locally Advanced ◽  
Developed Countries ◽  
Control Group ◽  
Preoperative Treatment ◽  
Discrete Elements ◽  
Important Indicator ◽  
Significant Difference

In recent years, breast cancer (BC) is the most common cancer pathology and the most common cause of disability among women in developed countries. Finding the most effective ways of interaction between the patient and the doctor creates the preconditions for the necessary analysis of the treatment process from an objective and subjective point of view. Therefore, an important indicator to be taken into account is the quality of life of a patient. To compare the indicators of a comprehensive assessment of the quality of life of patients to the adverse locally advanced forms (LA) of breast cancer before and after systemic intravenous polychemotherapy (SPCTx) and selective endolymphatic polychemotherapy (ELPCTx) in neoadjuvant mode. The study was conducted on the basis of a random analysis of outpatient cards from 112 patients with LA BC T4A-DN0-3M0 who received a comprehensive antitumor treatment on the basis of the Donetsk regional antitumor center and the University Clinic of the Odessa National Medical University from 2000 to 2017, which was proposed a questionnaire at various stages of preoperative treatment. The first (control) group consisted of 65 patients (58 %) with inoperable forms of LA BC, which was performed in neoadjuvant mode by SPCTx. The second (study group) included 47 patients (42 %) with inoperable forms of LA BC, which was performed as a neoadjuvant course ELPCTx. According to the integral indicators of quality of life and quality of health between patients in the control and study groups, there was no statistically significant difference. In a detailed analysis of the indicators of symptomatic scales, the difference between the groups did not exceed the critical. Based on the results of a study conducted among patients receiving endolymphatic chemotherapy in a neoadjuvant mode, the subjective evaluations of treatment in absolute numbers have better reference values without statistical superiority. The study of the integrative indicator of quality of life and its discrete elements is an ergonomic and economical means of heuristic assessment of the health of patients in order to further develop more rational and convenient ways of solving urgent issues of modern oncology by increasing compliance and finding a compromise between the physician and the patient.

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