scholarly journals Biomechanically distinct filter-feeding behaviors distinguish sei whales as a functional intermediate and ecologically flexible species

2021 ◽  
Vol 224 (9) ◽  
Author(s):  
Paolo S. Segre ◽  
Caroline R. Weir ◽  
Andrew Stanworth ◽  
Steve Cartwright ◽  
Ari S. Friedlaender ◽  
...  
Keyword(s):  
Rapid Evolution ◽  
Morphological Characteristics ◽  
Feeding Strategies ◽  
Unique Combination ◽  
Filter Feeding ◽  
Feeding Behaviors ◽  
Feeding Modes ◽  
Flexible Form ◽  
Continuous Filter ◽  
Shed Light

ABSTRACT With their ability to facultatively switch between filter-feeding modes, sei whales represent a functional and ecological intermediate in the transition between intermittent and continuous filter feeding. Morphologically resembling their lunge-feeding, rorqual relatives, sei whales have convergently evolved the ability to skim prey near the surface of the water, like the more distantly related balaenids. Because of their intermediate nature, understanding how sei whales switch between feeding behaviors may shed light on the rapid evolution and flexibility of filter-feeding strategies. We deployed multi-sensor bio-logging tags on two sei whales and measured the kinematics of feeding behaviors in this poorly understood and endangered species. To forage at the surface, sei whales used a unique combination of surface lunges and skim-feeding behaviors. The surface lunges were slow and stereotyped, and were unlike lunges performed by other rorqual species. The skim-feeding events featured a different filtration mechanism from the lunges and were kinematically different from the continuous filter feeding used by balaenids. While foraging below the surface, sei whales used faster and more variable lunges. The morphological characteristics that allow sei whales to effectively perform different feeding behaviors suggest that sei whales rapidly evolved their functionally intermediate and ecologically flexible form to compete with larger and more efficient rorqual species.

Associations Between Parent–Child Communication and Connectedness, Parent Feeding Behavior, and Child Body Mass in Pre-Adolescent Children

2020 ◽  
Author(s):  
Kristina D Lowe ◽  
Mark A Lott ◽  
Chad D Jensen
Keyword(s):  
Feeding Behavior ◽  
Body Mass ◽  
Weight Status ◽  
Community Sample ◽  
Feeding Strategies ◽  
Feeding Behaviors ◽  
Parent Child Communication ◽  
Parental Feeding ◽  
Parent Feeding ◽  
Parent Child

Abstract Objective  This study evaluated associations between parent–child connectedness and communication, parent feeding behaviors (restriction, pressure to eat, and monitoring), and age- and sex-standardized child body mass index (zBMI) in a sample of pre-adolescent children aged 8–12 years. Methods  A community sample of three hundred and eight child–parent dyads completed measures of communication and connectedness. Parents completed a feeding behavior measure and children were weighed and their height was measured. We examined whether parental feeding behaviors and parent–child communication and connectedness predicted child zBMI and whether parental feeding behaviors moderated the association between parent–child communication and connectedness and child zBMI. Results  Feeding restriction was positively associated with zBMI, while both pressure to eat and food monitoring exhibited negative associations with zBMI. Child-reported communication was inversely associated with zBMI and parental pressure to eat moderated this association such that lower pressure to eat predicted a stronger association between communication and zBMI. Conclusions  These findings are consistent with previous research suggesting that parent feeding strategies and parent–child communication are important contributors to child weight status. This study also provides preliminary evidence suggesting that adaptive parent–child communication is associated with lower body mass when parents avoid pressuring their child to eat. Our study provides an important extension of this body of research into middle childhood, a relatively understudied developmental stage.

A Monumental Horse Burial in the Armenian Highlands

2021 ◽  
Vol 49 (3) ◽  
pp. 41-50
Author(s):  
A. Nachmias ◽  
G. Bar-Oz ◽  
D. Nadel ◽  
I. Petrosyan ◽  
B. Gasparyan
Keyword(s):  
Morphological Characteristics ◽  
Radiometric Dating ◽  
Large Individual ◽  
Metal Ring ◽  
Tall Stature ◽  
Unique Combination ◽  
The Past

Here we report on the unprecedented discovery of the complete skeleton of a ritually interred adult stallion with a bronze ring in its mouth. The horse was buried in a unique 15-meters diameter monumental stone-built tomb excavated in the Aghavnatun necropolis located on the southern slopes of Mt. Aragats, in the northern fringes of the Ararat Depression, Republic of Armenia. The tumulus was roughly circular; the horse’s remains were found in situ, in an inner oval-shaped structure. Our methodological procedure included a detailed description of the burial, a taphonomic study of the bones, and meticulous morphometric observations and measurements, and thus we could provide a taxonomic defi nition and an age estimate. Direct radiometric dating of the horse’s skeleton provided a date of 2130±20 BP. The morphological characteristics of the horse, with its tall stature and slender feet, suggest that it was a large individual, similar to the extinct breed of Nisean horse previously known mainly from textual and iconographical sources. The metal ring found in the mouth of the horse suggests that it likely served as a breeding stallion. This discovery presents a unique combination of zooarchaeological evidence for the importance of the horse in the Parthian-Hellenistic worlds, and advances our understanding of the broad social signifi cance of the past breeding of equids in the Armenian Highlands.

Agreement processes in English and Spanish

2012 ◽  
Vol 19 (1) ◽  
pp. 58-88 ◽  
Author(s):  
Sara María Riveiro Outeiral ◽  
Juan Carlos Acuña-Fariña
Keyword(s):  
Constraint Satisfaction ◽  
Recent Literature ◽  
Morphological Characteristics ◽  
Grammatical Encoding ◽  
Linguistic Influences ◽  
Shed Light ◽  
Formal Operations

The nature of agreement has been the topic of extensive debate in the recent literature of both linguistics and psycholinguistics. In contrast to either fully syntactic or fully semantic accounts, so-called ‘constraint-satisfaction models’ (Haskell et al. 2010, among others) posit that all grammatical encoding is subject to a number of influences (syntax, semantics, pragmatics, frequency, etc.) which compete to dominate every computation, including agreement processes. After briefly considering psycholinguistic work on attraction (Wagers et al. 2009 and references therein), we try to shed light on this debate by observing how agreement operates in certain structures which were previously tested by Berg (1998) in a comparison of German and English. Here, we establish the same type of comparison between Spanish and English, and conclude that: 1. agreement is resolved after a constant tug-of-war between the syntactic and the semantic, a process in which semantics is likely to interfere in formal operations when these are performed in the context of a weak morphology; 2. agreement resolution is effectively subject to various linguistic influences, including the morphological characteristics of each language, but also the domain in which agreement is realised; and 3. agreement is responsible for shaping overall linguistic systems in the sense that, as noted by Berg, it may motivate left–orientation (as in English) or not (as in Spanish) as a general default strategy for locating subjects.

Fine structure and biology of Cryothecomonas gen. nov. (Protista incertae sedis) from the ice biota

1991 ◽  
Vol 69 (4) ◽  
pp. 1048-1070 ◽  
Author(s):  
Helge A. Thomsen ◽  
Kurt R. Buck ◽  
Patricia A. Bolt ◽  
David L. Garrison
Keyword(s):  
New Genus ◽  
Size Range ◽  
Morphological Characteristics ◽  
Lateral Position ◽  
Weddell Sea ◽  
Heterotrophic Flagellates ◽  
Unique Combination ◽  
Taxonomic Level ◽  
Incertae Sedis ◽  
Antarctic Waters

The morphology and ultrastructure of four species of Cryothecomonas gen.nov. (Protista incertae sedis) in material from the Weddell Sea, Antarctica, and the Isefjord, Denmark, are described. These heterotrophic flagellates, which were initially observed in association with sea ice, display a unique combination of morphological characteristics. At present it is impossible to assign the new genus to an existing higher taxonomic level of protistan flagellates. Cryothecomonas species are furnished with a close-fitting multilayered theca. The two naked anterior flagella emerge through narrow thecal funnels. A transitional helix is part of the flagellar transition zone. A conspicuous cytostome is located in a posterior (lateral) position. Food uptake is mediated through the extension of cytostomal pseudopodia. The nucleus is anteriorly located and contains a conspicuous nucleolus and distinct areas of chromatin. Mitochondrial cristae are tubular. Cryothecomonas species feed on cells in the size range 2–4.5 μm (e.g., algal flagellates). Data are presented on the abundance of Cryothecomonas armigera sp.nov. in Antarctic waters.

scholarly journals A new species of Berkheya (Asteraceae, Arctotideae) from the Northern Cape, South Africa

Bothalia ◽  
2014 ◽  
Vol 44 (1) ◽  
Author(s):  
Nicola G. Bergh ◽  
Nick A. Helme
Keyword(s):  
South Africa ◽  
New Species ◽  
Morphological Characteristics ◽  
Small Population ◽  
Unique Combination ◽  
International Union ◽  
Northern Cape ◽  
Tall Shrub ◽  
A New Species ◽  
African Genus

Background: Berkheya is a large, mainly southern African genus of approximately 75 species, several of which are poorly known and under-collected. Since revision in 1959, only a few new species have been described. Publication of new taxa facilitates conservation objectives and contributes to a better understanding of the southern African flora.Objectives: The objectives of this study were to describe a new species of Berkheya, consider its taxonomic position within the genus and assess its conservation status.Methods: Macromorphology and micromorphology of the new species were compared with known species.Results: Berkheya dumicola N.G.Bergh Helme was described from two subpopulations from the northern Bokkeveld escarpment, Northern Cape Province, South Africa. The species is a tall shrub with radiate flowerheads, toothed receptacle alveole margins, a uniseriate pappus of small, rounded scales and very short twin-hairs on the cypsela.Conclusion: Berkheya dumicola is a new species with a unique combination of features. Based on morphological characteristics, its closest relative within the genus is likely to be the recently describedBerkheya chrysanthemoides J.C.Manning Goldblatt. The limited geographic extent and small population size of B. dumicola warrant an International Union for Conservation of Nature (IUCN) status of ‘Endangered’.

scholarly journals Light spectra regulated foraging and feeding behaviors shed light on stock enhancement of the sea urchin Strongylocentrotus intermedius

2020 ◽  
Vol 18 ◽  
pp. 100480
Author(s):  
Mingfang Yang ◽  
Zhouling Chen ◽  
Fangyuan Hu ◽  
Jiangnan Sun ◽  
Jingyun Ding ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Stock Enhancement ◽  
Strongylocentrotus Intermedius ◽  
Feeding Behaviors ◽  
Light Spectra ◽  
Shed Light

scholarly journals Morphological and biomechanical disparity of crocodile-line archosaurs following the end-Triassic extinction

2013 ◽  
Vol 280 (1770) ◽  
pp. 20131940 ◽  
Author(s):  
Thomas L. Stubbs ◽  
Stephanie E. Pierce ◽  
Emily J. Rayfield ◽  
Philip S. L. Anderson
Keyword(s):  
Late Cretaceous ◽  
Morphological Variation ◽  
Late Triassic ◽  
Complex Relationship ◽  
Ecological Diversity ◽  
Unique Combination ◽  
Morphological Disparity ◽  
Selective Pressures ◽  
Feeding Modes ◽  
Jaw Biomechanics

Mesozoic crurotarsans exhibited diverse morphologies and feeding modes, representing considerable ecological diversity, yet macroevolutionary patterns remain unexplored. Here, we use a unique combination of morphological and biomechanical disparity metrics to quantify the ecological diversity and trophic radiations of Mesozoic crurotarsans, using the mandible as a morpho-functional proxy. We recover three major trends. First, the diverse assemblage of Late Triassic crurotarsans was morphologically and biomechanically disparate, implying high levels of ecological variation; but, following the end-Triassic extinction, disparity declined. Second, the Jurassic radiation of marine thalattosuchians resulted in very low morphological disparity but moderate variation in jaw biomechanics, highlighting a hydrodynamic constraint on mandibular form. Third, during the Cretaceous terrestrial radiations of neosuchians and notosuchians, mandibular morphological variation increased considerably. By the Late Cretaceous, crocodylomorphs evolved a range of morphologies equalling Late Triassic crurotarsans. By contrast, biomechanical disparity in the Cretaceous did not increase, essentially decoupling from morphology. This enigmatic result could be attributed to biomechanical evolution in other anatomical regions (e.g. cranium, dentition or postcranium), possibly releasing the mandible from selective pressures. Overall, our analyses reveal a complex relationship between morphological and biomechanical disparity in Mesozoic crurotarsans that culminated in specialized feeding ecologies and associated lifestyles.

scholarly journals Taqsīm as a Creative Musical Process in Arabic Music

2021 ◽  
Vol 12 ◽  
Author(s):  
Zaher Alkaei ◽  
Mats B. Küssner
Keyword(s):  
Content Analysis ◽  
Qualitative Interviews ◽  
Cross Cultural ◽  
Tonal Music ◽  
Creative Processes ◽  
Thematic Content Analysis ◽  
Multiple Components ◽  
Flexible Form ◽  
Arabic Music ◽  
Shed Light

Creativity plays a major role in various musical contexts including composition, performance and education. Although numerous studies have revealed how creativity is involved in processes of listening, improvising and composing, relatively little is known about the particularities of transcultural creative processes in music. In this article, we aim to shed light on the creative musical processes underlying taqsīm performance in Arabic music. To that end, qualitative interviews have been conducted with three Berlin-based oud players from Syria. Results of a thematic content analysis show that taqsīm encompasses multiple components (e.g., a flexible form and dependency on maqam as well as tonal music) and serves various functions such as developing artistic individuality. Moreover, taqsīm is affected by interactions between tradition and novelty. We discuss the interview data within the cross-cultural experiential model of musical creativity developed by Hill (2018), offering a fresh approach to studying taqsīm which goes beyond established concepts such as the improvisation-composition continuum.

The significance of contrasting feeding strategies on the reproductive cycle in two coexisting tellinacean bivalves

2002 ◽  
Vol 82 (3) ◽  
pp. 443-453 ◽  
Author(s):  
R.A. Stead ◽  
E. Clasing ◽  
M.A. Lardies ◽  
L.P. Arratia ◽  
G. Urrutia ◽  
...  
Keyword(s):  
Feeding Strategies ◽  
Centric Diatom ◽  
Spawning Period ◽  
Central Chile ◽  
South Central ◽  
Bottom Deposits ◽  
Feeding Modes ◽  
Lower Intertidal Zone ◽  
Diatom Density ◽  
Reproductive Cycles

Semele solida and Tagelus (Tagelus) dombeii are two tellinacean bivalves which coexist in the lower intertidal zone of a sandflat in south-central Chile but follow different feeding strategies. Wheras T. (T.) dombeii is a suspension-feeder, S. solida is a facultative deposit-feeder. In this study, digestive gland indices and reproductive cycles were described in relation to annual food availability and related to their feeding modes. Results showed that gonadic index cycles were similar for both species, with highest values being observed during the spring when water temperature was still on the rise and microflagellate and centric diatom density was at its peak. However, histological analyses indicated that the spawning period of T. (T.) dombeii extended from November 1995 to March 1996 and from August 1996 to January 1997, whereas S. solida presented a continuous spawning period that extended from September 1995 to December 1996. Results suggest that extended spawning throughout the winter by S. solida is a consequence of its ability to feed on bottom deposits when food in suspension is low.

Ecomorphology of the Tongues of Australian Megachiroptera (Chiroptera: Pteropodidae)

1997 ◽  
Vol 45 (4) ◽  
pp. 369 ◽  
Author(s):  
Patrina Birt ◽  
Leslie S. Hall ◽  
Geoffrey C. Smith
Keyword(s):  
Seed Dispersal ◽  
Feeding Behaviour ◽  
Food Source ◽  
Morphological Characteristics ◽  
Feeding Strategies ◽  
Field Observations ◽  
Nectar Feeding

The tongues of six species of Australian megachiropterans were studied macroscopically and microscopically to observe whether there were any morphological characteristics correlating with their foraging and feeding behaviour. Tongues varied from being extensible and brush-like (with long hair-like papillae) in Syconycteris australis, to club-like (with very few types of papillae) in Nyctimene robinsoni, to long-pointed (possessing several types of surface papillae) in the Pteropus species. The morphology of the tongue of S. australis and the Pteropus species was similar to that of nectar-feeding birds, marsupials and other mammals. N. robinsoni possessed a tongue highly structured for processing the fruit on which it feeds, whilst the tongue of the S. australis and P. scapulatus was highly structured for a diet predominantly made up of nectar. Although the surface papillae were similar among P. poliocephalus, P. alecto and P. conspicillatus, the shape of the tongue varied considerably, suggesting that there may be subtle differences between individual feeding strategies. The morphology of the tongues in this study, combined with field observations, suggest that many megachiropterans are able to consume different food types when their preferred food source is unavailable. In addition, the structure of tongue and its papillae support the role of megachiropterans in both pollination and seed dispersal.

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