scholarly journals Grasping the shape of belemnoid arm hooks—a quantitative approach

Paleobiology ◽  
2017 ◽  
Vol 43 (2) ◽  
pp. 304-320 ◽  
Author(s):  
René Hoffmann ◽  
Manuel F. G. Weinkauf ◽  
Dirk Fuchs

AbstractChitinous arm hooks (onychites) of belemnoid coleoid cephalopods are widely distributed in Mesozoic sediments. Due to their relative abundance and variable morphology compared with the single, bullet-shaped, belemnite rostrum, arm hooks came into the focus of micropaleontologists as a promising index fossil group for the Jurassic–Cretaceous rock record and have been the target of functional, ecological, and phylogenetic interpretations in the past. Based on three well-preserved arm crowns of the Toarcian diplobelid Chondroteuthis wunnenbergi, we analyzed the shape of a total of 87 micro-hooks. The arm crown of Chondroteuthis is unique in having uniserial rather than biserial hooks. The first application of elliptic Fourier shape analysis to the arm weapons of belemnoid coleoids allows for the distinction of four micro-hook morphotypes and the quantification of shape variation within these morphotypes. Based on the best-preserved arm crown, we reconstructed the distribution of morphotypes within the arm crown and along a single arm. Our quantitative data support former observations that smaller hooks were found close to the mouth and at the most distal arm parts, while the largest hooks were found in the central part of the arm crown. Furthermore, we found a distinct arm differentiation, as not every arm was equipped with the same hook morphotype. Here, we report the functional specialization of the belemnoid arm crown for the first time and speculate about the potential function of the four morphotypes based on comparisons with modern cephalopods. Our analyses suggest a highly adapted functional morphology and intra-individual distribution of belemnoid hooks serving distinct purposes mainly during prey capture.


Author(s):  
DUANE T. EPPLER ◽  
ROBERT EHRLICH ◽  
DAG NUMMEDAL ◽  
PETER H. SCHULTZ


2020 ◽  
Vol 89 (3) ◽  
pp. 282-323 ◽  
Author(s):  
Carolin Gut ◽  
Jasna Vukić ◽  
Radek Šanda ◽  
Timo Moritz ◽  
Bettina Reichenbacher

Gobies (Gobiidae + Oxudercidae) are among the largest groups of extant marine fishes. Fossils of gobies are abundant since the Miocene, and many species have been reported so far. However, delimitation of fossil goby species is challenging because molecular markers and diagnostic traits such as the disposition of sensory head papillae are lost. This study provides, for the first time, an actualistic framework for the identification of fossil goby species. We focus on characters that can in principle be recognized in fossils, and evaluate their ability to discriminate between extant goby species based on statistical analyses. Using 14 extant species of Gobius and seven species of Pomatoschistus, we conducted otolith morphometry, elliptic Fourier shape analysis of otoliths using the package ‘Momocs’, conventional fish morphometry, and meristic counts. In addition, the otoliths of all species are depicted based on SEM images and briefly described. Otolith Fourier shape analysis proved to be most efficient in discrimination of species within both genera, Gobius and Pomatoschistus. Several characters used in the other approaches also worked well, but the results were variable, and the relative taxonomic significance of particular variables tended to change depending on the species under consideration. We propose otolith shape analysis as a powerful tool to explore ancient goby species diversity when samples with abundant fossil otoliths are present. Overall, the herein presented data will greatly facilitate delimitation of fossil goby species in future studies, and will consequently shed new light on the evolution of goby diversity and biogeography through time.



2021 ◽  
pp. 1-10
Author(s):  
Baran Karapunar ◽  
Winfried Werner ◽  
Franz T. Fürsich ◽  
Alexander Nützel

Abstract Protandrous sex change (sex change from male to female) is one of the diverse sexual expressions exhibited by bivalves, but its expression in the shell is quite rare. Previous studies on living and fossil astartids suggest a relationship between protandrous sex change and the formation of crenulations on the ventral shell margin at later ontogenetic stages. Here we report the formation of such crenulations in the Early Jurassic astartid Nicaniella rakoveci (Kuhn, 1935) from the Amaltheenton Formation at Buttenheim, Franconia. This is the earliest known record of protandrous hermaphroditism in fossil bivalves, predating previous reports by at least 13 Myr. A principal component analysis of linear size measurements and Fourier shape analysis of the shell outlines revealed that the outline of Nicaniella rakoveci specimens varies from subquadrate to subcircular, but this variation is independent of the presence or absence of crenulations and therefore not associated with sex. Crenulated specimens exhibit a lower height/inflation ratio than non-crenulated ones, suggesting that the protandrous females have more inflated valves than the males. The formation of crenulations was probably related to allocation of resources for reproduction. The most likely function of the crenulations was to increase the internal shell volume in the female stage to accommodate more eggs rather than being an adaptation against predation as often assumed for other bivalves. The formation of crenulations is part of the protandrous life history and probably is controlled by a genetic mechanism that is also responsible for sex change.



Author(s):  
Nele Nauwelaers ◽  
Harold Matthews ◽  
Yi Fan ◽  
Balder Croquet ◽  
Hanne Hoskens ◽  
...  


2011 ◽  
Vol 26 (S2) ◽  
pp. 1893-1893
Author(s):  
I. Manor ◽  
G. Yazpan

ADHD is a well-known, chronic disorder that persists in adulthood. During the past 20 years its existence in adults is becoming clearer, yet its dynamic aspects are rarely discussed. The treatment of adults is vital, as much as that of children; however the literature discussing it, especially its non-pharmacological aspect, is scarce.We describe the results of our treatment with drama-therapy of two groups of adults with ADHD. These groups included 11 adults (from both groups), men and women, from most socioeconomic strata, aged ≥ 60 yrs., who were diagnosed as suffering from ADHD and were treated for it for the first time in their life. Drama-therapy was selected as we believed it to be a useful method with associative, distracted ADHD patients, since it enabled the use of transitional space through non-verbal images and acts.This presentation discusses the basic themes with which patients began therapy. Interestingly, all patients, however different, shared the same themes that were built on self doubt and the pre-presumption of disappointment. The impairment related to ADHD, that was felt, but not understood, led to a strong experience of heavy losses, which we tried to define separately: of a clear path, of control, of the inner perception of borders and of the loss of an integrative inner self. All these losses were accumulated in the transitional space in a place we named “Nowhere land”.We would like to present these themes of losses and of becoming lost and to discuss their meaning.



Exchange ◽  
1982 ◽  
Vol 11 (1) ◽  
pp. 48-57

AbstractMons. Antonio Batista Fragoso has been bishop of Crateus in Northeast Brazil for the past ten years. Eighty percent of the 360,000 people in his diocese are impoverished peasants who engage in rudimentary farming. At least half of the peasants are landless. It is among these people that Bishop Fragoso has encouraged the formation of small grassroots Christian communities that are responsible for a profound change in the patterns of Christian living in his diocese. The following is LP's translation of excerpts from a talk that Bishop Fragoso gave to his fellow bishops and priests in Managua in October, 1980. This is the first time it has appeared in English. (Editor Latinamerica Press)



2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Simon Reich ◽  
Dajie Zhang ◽  
Tomas Kulvicius ◽  
Sven Bölte ◽  
Karin Nielsen-Saines ◽  
...  

AbstractThe past decade has evinced a boom of computer-based approaches to aid movement assessment in early infancy. Increasing interests have been dedicated to develop AI driven approaches to complement the classic Prechtl general movements assessment (GMA). This study proposes a novel machine learning algorithm to detect an age-specific movement pattern, the fidgety movements (FMs), in a prospectively collected sample of typically developing infants. Participants were recorded using a passive, single camera RGB video stream. The dataset of 2800 five-second snippets was annotated by two well-trained and experienced GMA assessors, with excellent inter- and intra-rater reliabilities. Using OpenPose, the infant full pose was recovered from the video stream in the form of a 25-points skeleton. This skeleton was used as input vector for a shallow multilayer neural network (SMNN). An ablation study was performed to justify the network’s architecture and hyperparameters. We show for the first time that the SMNN is sufficient to discriminate fidgety from non-fidgety movements in a sample of age-specific typical movements with a classification accuracy of 88%. The computer-based solutions will complement original GMA to consistently perform accurate and efficient screening and diagnosis that may become universally accessible in daily clinical practice in the future.



Zootaxa ◽  
2021 ◽  
Vol 4996 (3) ◽  
pp. 492-512
Author(s):  
PAN-WEN HSUEH

Two new species and one new record species of the genus Pseudonereis are described from specimens collected from ecological surveys of coasts of Taiwan and an offshore island during the past 15 years: P. jihueiensis n. sp., P. kihawensis n. sp., and P. trimaculata. Epitokes of P. jihueiensis n. sp. and P. trimaculata are also described. Pseudonereis jihueiensis n. sp. can be distinguished from congeners by having edentate jaws, χ-shaped ridge pattern of Areas VI–V–VI, parapodial morphology (i.e., length ratio of dorsal cirrus to dorsal ligule or presence of small pennant-like dorsal ligule, shape of dorsal ligule in certain region of chaetigers), and no heterogomph spinigers in the subacicular fascicle of the neuropodia. Pseudonereis kihawensis n. sp. differs from congeners by having crescent-shaped pointed-bars in Area VI, λ-shaped ridge pattern of Areas VI–V–VI, parapodial morphology (i.e., length ratio of dorsal cirrus to dorsal ligule or presence of small pennant-like dorsal ligule or shape of dorsal ligule in certain region of chaetigers), and no heterogomph spinigers in the subacicular fascicle of the neuropodia. Pseudonereis trimaculata, a species originally described from Indonesia, is reported from Taiwan for the first time. A table of key characters for all species of Pseudonereis is provided.  



Belleten ◽  
2012 ◽  
Vol 76 (276) ◽  
pp. 385-402
Author(s):  
Murat Kılıç

The origins of the imperial cult in Smyrna date back to the Hellenistic period. It is a fact that political concerns were effective in the generation of such cults. Predicting the super power of the future and proving to be a loyal ally whilst acting in satisfactory behaviors were essential factors. The right preference made between two fighting or contending powers ensured that a city would benefit from various privileges in the future. For example, Symrna, which had established a cult in the city previously on behalf of Stratonice, the mother of Antiochus II of Seleucid dynasty, would do the same by building a temple in the name of the dty of Rome for the first time in Asia in 195 BC, after recognizing the rising power. Later on, while giving permission to the provinces that wanted to establish an imperial cult, the Roman emperors and the Senate would consider first, their relationships with Rome in the past and second, their origins. Smyrna, building its relationships with the Roman state on a solid basis, was granted the title of neokoros three times by the Roman Emperors Tiberius, Hadrianus and Caracalla, respectively. In this essay, the development of the Roman imperial cult in Smyrna is discussed within the historical process outlined above. An attempt has been made to put forth new opinions about the issue by discussing the academicians' evaluations on the imperial cult, which apparently was effectively executed in Smyrna between the first and third centuries AD, with the support of epigraphic and numismatic evidences.



2018 ◽  
Vol 19 (5) ◽  
pp. 339-359
Author(s):  
Richard W. Hill ◽  
Daniel Coleman

This co-authored article examines the oldest known treaty between incoming Europeans and Indigenous North Americans to derive five basic principles to guide healthy, productive relationships between Indigenous community-based researchers and university-based ones. Rick Hill, Tuscarora artist and knowledge keeper from the Six Nations of the Grand River, publishes for the first time here the most complete oral history that exists today of that ancient treaty, from the early seventeenth century, known as the Two Row Wampum or the Covenant Chain agreement. Interspersed with Dr. Hill’s reflections, Daniel Coleman, a settler professor of English and Cultural Studies at McMaster University, outlines five principles for research partnerships derived from the discussions of the Two Row Research Partnership seminars that Hill and Coleman have been hosting at Deyohahá:ge: Indigenous Knowledge Centre for the past four years. Formed between the Hodinöhsö:ni’ confederacy and Dutch merchants arriving near Albany, New York in 1609, the Two Row Wampum-Covenant Chain treaty set the precedent for nation-to-nation treaties between European colonial powers and Indigenous peoples with two parallel rows representing the Hodinöhsö:ni’ canoe and the Dutch ship sailing down the shared river. Each party agreed to keep their beliefs and laws in their separate vessels, and on this basis of interdependent autonomy, they established a long-lasting friendship. This article suggests that by renewing our understanding of the Two Row Wampum-Covenant Chain treaty, Indigenous and non-Indigenous researchers alike can rebuild relationships of trust and cooperation that can decolonize Western presumptions and re-establish healthy and productive research partnerships.



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