scholarly journals Conjugation in Euplotes raikovi (Protista, Ciliophora): New Insights into Nuclear Events and Macronuclear Development from Micronucleate and Amicronucleate Cells

2020 ◽  
Vol 8 (2) ◽  
pp. 162 ◽  
Author(s):  
Ruitao Gong ◽  
Yaohan Jiang ◽  
Adriana Vallesi ◽  
Yunyi Gao ◽  
Feng Gao
Keyword(s):  
Distinct Group ◽  
Marine Species ◽  
New Information ◽  
Sexual Process ◽  
Nuclear Events ◽  
Nuclear Changes ◽  
Nuclear Differentiation ◽  
Euplotes Raikovi ◽  
First Time ◽  
Mitosis And Meiosis

Ciliates form a distinct group of single-celled eukaryotes that host two types of nuclei (micro and macronucleus) in the same cytoplasm and have a special sexual process known as conjugation, which involves mitosis, meiosis, fertilization, nuclear differentiation, and development. Due to their high species diversity, ciliates have evolved different patterns of nuclear events during conjugation. In the present study, we investigate these events in detail in the marine species Euplotes raikovi. Our results indicate that: (i) conjugation lasts for about 50 h, the longest stage being the development of the new macronucleus (ca. 36 h); (ii) there are three prezygotic micronuclear divisions (mitosis and meiosis I and II) and two postzygotic synkaryon divisions; and (iii) a fragment of the parental macronucleus fuses with the new developing macronucleus. In addition, we describe for the first time conjugation in amicronucleate E. raikovi cells. When two amicronucleate cells mate, they separate after about 4 h without evident nuclear changes; when one amicronucleate cell mates with a micronucleate cell, the micronucleus undergoes regular prezygotic divisions to form migratory and stationary pronuclei, but the two pronuclei fuse in the same cell. In the amicronucleate cell, the parental macronucleus breaks into fragments, which are then recovered to form a new functional macronucleus. These results add new information on the process of conjugation in both micronucleate and amicronucleate Euplotes cells.

scholarly journals Morphogenesis of the Ciliature During Sexual Process of Conjugation in the Ciliated Protist Euplotes raikovi

2021 ◽  
Vol 7 ◽  
Author(s):  
Usman Asghar ◽  
Yong Chi ◽  
Yunyi Gao ◽  
Borong Lu ◽  
Yaohan Jiang ◽  
...  
Keyword(s):  
De Novo ◽  
Anterior Part ◽  
Posterior Part ◽  
Marine Species ◽  
Ventral Side ◽  
Fragmentation Pattern ◽  
Morphogenetic Process ◽  
Stable Pattern ◽  
Sexual Process ◽  
Euplotes Raikovi

Morphogenesis is an important process that widely occurs in almost all the organisms, including the ciliated protists. Ciliates are a large group of single-celled eukaryotes that can reproduce asexually (e.g., binary fission) and perform sexual process (e.g., conjugation). Morphogenesis happens in both asexual reproduction and sexual process in ciliates and the reorganization during conjugation is more complex. However, studies of morphogenesis focusing on conjugation are very limited. Here we studied the morphogenetic process during conjugation in the marine species Euplotes raikovi Agamaliev, 1966. The results indicate that: (1) the ciliature in the ventral side reorganizes twice during sexual process, i.e., conjugational and postconjugational reorganization; (2) the adoral zone of membranelles (AZM) is generated de novo in a pouch beneath the cortex during both reorganizations, with the anterior part generated during the first reorganization, while the posterior part formed during the second reorganization; (3) the frontoventral-transverse (FVT) cirri anlagen are formed de novo in both processes with the fragmentation pattern of 2:2:3:3:2; (4) one left marginal cirrus is generated de novo during both reorganizations; and (5) the dorsal ciliature remains intact during the whole process, except that the two caudal cirri originate from the end of the right-most two dorsal kineties during both reorganizations. Comparisons of the morphogenetic process during conjugation demonstrate a considerably stable pattern within Euplotes while the patterns vary dramatically among different ciliate groups.

A memoir of Hugh Miller (1802–1856) attributed to his son Hugh Miller FGS (1850–1896)

2017 ◽  
Vol 44 (1) ◽  
pp. 103-109 ◽  
Author(s):  
M. A. Taylor
Keyword(s):  
Family Member ◽  
New Information ◽  
Newspaper Editor ◽  
Interesting Contribution ◽  
First Time

A manuscript memoir of Hugh Miller (1802–1856), geologist, writer and newspaper editor, is attributed to his son Hugh Miller FGS (1850–1896). It is published here, apparently for the first time. It was written sometime in 1881–1896, more probably 1882–1895. Its intended place of publication is discussed. It is an interesting contribution to Miller biography, written by a family member and providing some new information and anecdotes.

scholarly journals Hearing from the ocean and into the river: the evolution of the inner ear of Platanistoidea (Cetacea: Odontoceti)

Paleobiology ◽  
2021 ◽  
pp. 1-21
Author(s):  
Mariana Viglino ◽  
Maximiliano Gaetán ◽  
Mónica R. Buono ◽  
R. Ewan Fordyce ◽  
Travis Park
Keyword(s):  
Inner Ear ◽  
High Frequency ◽  
Sound Production ◽  
Marine Species ◽  
Late Oligocene ◽  
Evolutionary Patterns ◽  
Ear Morphology ◽  
Cochlear Morphology ◽  
First Time ◽  
Hearing Abilities

Abstract The inner ear of the two higher clades of modern cetaceans (Neoceti) is highly adapted for hearing infrasonic (mysticetes) or ultrasonic (odontocetes) frequencies. Within odontocetes, Platanistoidea comprises a single extant riverine representative, Platanista gangetica, and a diversity of mainly extinct marine species from the late Oligocene onward. Recent studies drawing on features including the disparate tympanoperiotic have not yet provided a consensus phylogenetic hypothesis for platanistoids. Further, cochlear morphology and evolutionary patterns have never been reported. Here, we describe for the first time the inner ear morphology of late Oligocene–early Miocene extinct marine platanistoids and their evolutionary patterns. We initially hypothesized that extinct marine platanistoids lacked a specialized inner ear like P. gangetica and thus, their morphology and inferred hearing abilities were more similar to those of pelagic odontocetes. Our results reveal there is no “typical” platanistoid cochlear type, as the group displays a disparate range of cochlear anatomies, but all are consistent with high-frequency hearing. Stem odontocete Prosqualodon australis and platanistoid Otekaikea huata present a tympanal recess in their cochlea, of yet uncertain function in the hearing mechanism in cetaceans. The more basal morphology of Aondelphis talen indicates it had lower high-frequency hearing than other platanistoids. Finally, Platanista has the most derived cochlear morphology, adding to evidence that it is an outlier within the group and consistent with a >9-Myr-long separation from its sister genus Zarhachis. The evolution of a singular sound production morphology within Platanistidae may have facilitated the survival of Platanista to the present day.

scholarly journals Impacts of stratospheric aerosol geoengineering strategy on Caribbean coral reefs

2018 ◽  
Vol 10 (4) ◽  
pp. 523-532 ◽  
Author(s):  
Zhihua Zhang ◽  
Andy Jones ◽  
M. James C. Crabbe
Keyword(s):  
Coral Reefs ◽  
Climate Model ◽  
Marine Species ◽  
Stratospheric Aerosol ◽  
Solar Irradiation ◽  
Content Type ◽  
Hurricane Damage ◽  
Carbon Emissions Reduction ◽  
Caribbean Coral Reefs ◽  
First Time

Purpose Currently, negotiation on global carbon emissions reduction is very difficult owing to lack of international willingness. In response, geoengineering (climate engineering) strategies are proposed to artificially cool the planet. Meanwhile, as the harbor around one-third of all described marine species, coral reefs are the most sensitive ecosystem on the planet to climate change. However, until now, there is no quantitative assessment on the impacts of geoengineering on coral reefs. This study aims to model the impacts of stratospheric aerosol geoengineering on coral reefs. Design/methodology/approach The HadGEM2-ES climate model is used to model and evaluate the impacts of stratospheric aerosol geoengineering on coral reefs. Findings This study shows that (1) stratospheric aerosol geoengineering could significantly mitigate future coral bleaching throughout the Caribbean Sea; (2) Changes in downward solar irradiation, sea level rise and sea surface temperature caused by geoengineering implementation should have very little impacts on coral reefs; (3) Although geoengineering would prolong the return period of future hurricanes, this may still be too short to ensure coral recruitment and survival after hurricane damage. Originality/value This is the first time internationally to quantitatively assess the impacts of geoengineering on coral reefs.

45° REFLECTOMETRY OF SEMICONDUCTOR QUANTUM WELLS

2001 ◽  
Vol 15 (17n19) ◽  
pp. 683-687
Author(s):  
A. SILVA-CASTILLO ◽  
F. PEREZ-RODRIGUEZ
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Growth Direction ◽  
Angle Of Incidence ◽  
Near Surface ◽  
New Information ◽  
Difference Formula ◽  
Exciton Polaritons ◽  
The Difference ◽  
First Time

We have applied the 45° reflectometry for the first time to study exciton-polaritons in quantum wells. The 45° reflectometry is a new polarization-modulation technique, which is based on the measurement of the difference [Formula: see text] between the p-polarization reflectivity (Rp) and the squared s-polarization reflectivity [Formula: see text] at an angle of incidence of 45°. We show that [Formula: see text] spectra may provide qualitatively new information on the exciton-polariton modes in a quantum well. These optical spectra turn out to be very sensitive to the zeros of the dielectric function along the quantum-well growth direction and, therefore, allow to identify the resonances associated with the Z exciton-polariton mode. We demonstrate that 45° reflectometry could be a powerful tool for studying Z exciton-polariton modes in near-surface quantum wells, which are difficult to observe in simple spectra of reflectivity Rp

Reading literacy and periphrastic capacity in the context of individual language development

2021 ◽  
Vol 82 (1) ◽  
pp. 7-15
Author(s):  
E. V. Arkhipova ◽  
L. V. Lagunova
Keyword(s):  
Information Age ◽  
Russian Language ◽  
Reading Literacy ◽  
Informational Texts ◽  
Pedagogical Discourse ◽  
Cultural Concepts ◽  
New Information ◽  
Didactic Texts ◽  
First Time ◽  
The Russian Language

The aim of the study was to develop linguistic and methodological theoretical aspects of training the skill of paraphrasing, which constitutes an important element of reading literacy. To this end, the authors reviewed research and educational publications in the field of teaching the Russian language and conducted a pedagogical experiment to analyse pedagogical processes. Interrelation between the infosphere and axiosphere of Russian language lessons within the pedagogical discourse involves the division of didactic texts into informational and axiological, including modern linguistic and ethnographic texts that manifest Russian cultural concepts in the new information age. It is shown that various aspects of teaching paraphrasing and interpretation techniques on the basis of informational texts have already been elucidated quite efficiently. However, formation of the axiological component of reading literacy (teaching to paraphrase on the basis of linguo-ethnographic texts) has been undertaken within the framework of the present study for the first time. These issues should be considered comprehensively, in the context of language and values-based development of a personality.

scholarly journals The genus Xiphinema in South Africa. XXVI. New information on X. bolandium, with description of the four juvenile stages (Nematoda: Longidoridae)

Koedoe ◽  
2001 ◽  
Vol 44 (2) ◽  
Author(s):  
J. Heyns
Keyword(s):  
South Africa ◽  
Western Cape ◽  
Eastern Cape Province ◽  
Eastern Cape ◽  
Western Cape Province ◽  
New Information ◽  
Wilderness Area ◽  
Juvenile Stages ◽  
First Time ◽  
New Distribution

A population of Xiphinema bolandium from the Baviaanskloof Wilderness Area in the Eastern Cape Province was studied, and the four juvenile stages described and figured for the first time. New distribution records are listed from several localities in the Western Cape Province, mostly from vineyards and peach orchards, as well as from fynbos.

scholarly journals New locations of rare and protected plant species of the aquatic ecosystems of Minsk Region and National park “Belovezhskaya Pushcha”

2018 ◽  
Vol 63 (4) ◽  
pp. 437-446
Author(s):  
K. L. Savitskaya ◽  
М. A. Dzhus
Keyword(s):  
Plant Species ◽  
National Park ◽  
Aquatic Plant ◽  
New Information ◽  
New Locations ◽  
Salvinia Natans ◽  
The Republic ◽  
Data Deficient ◽  
First Time ◽  
Berula Erecta

There is a review of floral studies of the water bodies in Minsk Region and National Park “Belovezhskaya Pushcha”. 75 new locations of 20 rare aquatic and riverside plant species coming at the water and 1 hybrid were found. 7 of these species are listed in the Red Book of the Republic of Belarus, 5 species are included into the category of Least Concern and Data Deficient. Potamogeton berchtoldii Fieber, Utricularia minor L., Potamogeton acutifolius Link, P. nodosus Poir., Salvinia natans (L.) All. are reported for the first time from National Park «Belovezhskaya Pushcha». The spreading of Berula erecta (Huds.) Coville on the territory of National Park is considered in detail. New locations of Nuphar pumila (Timm) DC., Ranunculus kauffmannii Clerc., Najas major All., Berula erecta, Glyceria lithuanica (Gorski) Gorski, Conioselinum tatari­ cum Hoffm. in Minsk Region, which were not included in 4th edition of the Red Book, have been described. A brief description of habitat environmental conditions is given for the revealed species of aquatic plants, and their phytocoenotic confinement is also pointed out. New information on the locations of protected aquatic plant species should be used to monitor their populations and prepare the documents of protection.

scholarly journals Ethnomedicinal plants used for the treatment of dermatological affections on the Purépecha Plateau, Michoacán, Mexico

2018 ◽  
pp. 95-132 ◽  
Author(s):  
Roberto Esquivel-García ◽  
Emmanuel Pérez-Calix ◽  
Alejandra Ochoa-Zarzosa ◽  
Martha Estrella García-Pérez
Keyword(s):  
Medicinal Plants ◽  
Plant Species ◽  
Aloe Vera ◽  
Skin Inflammation ◽  
Aerial Parts ◽  
Informant Consensus ◽  
Ancestral Knowledge ◽  
New Information ◽  
Use Values ◽  
First Time

Background and Aims: Inhabitants of the Purépecha Plateau preserve an excellent ancestral knowledge on medicinal plants used for dermatological affections, which has not been documented. An ethnopharmacological survey was carried out in this region to gather information on the use of medicinal plants and herbal preparations for treating dermatological affections, to disseminate the Purépecha indigenous knowledge and identifying promising plants for developing new formulations for cutaneous conditions.Methods: The study was conducted in the 21 municipalities that compose the Purépecha Plateau. A total of 86 local inhabitants (62 women and 24 men) were interviewed. The data were quantitatively analyzed through the determination of the use value, fidelity level and informant consensus factor.Key results: A total of 97 plant species belonging to 47 families were documented for treating 19 dermatological conditions on the Purépecha Plateau. Asteraceae was the leading family among the collected medicinal plants (20.61%), followed by Lamiaceae (13.40%) and Solanaceae (5.15%). The largest number of plants was used for the treatment of cuts (40.20%), skin inflammation (37.11%) and rash (37.11%). The aerial parts were the most commonly used (34.75%). The medicinal plant species with larger use values were Heterotheca inuloides (0.53), Aloe vera (0.37) and Oenothera rosea (0.21). The comparison of results with ethnomedicinal literature worldwide revealed that 8.25% of plants used on the Purépecha Plateau were recorded for the first time for the treatment of dermatological affections.Conclusions: This study provides new information on medicinal plants used on the Purépecha Plateau to treat cutaneous diseases. Future pharmacological and toxicological investigations are required to demonstrate the efficacy and safety of these species for treating dermatological affections.

New and unpublished data about the ground beetles (Coleoptera: Carabidae) from the subfamily Trechinae of Bulgaria

2021 ◽  
Vol 26 (2) ◽  
Author(s):  
TEODORA TEOFILOVA
Keyword(s):  
Endemic Species ◽  
Sampling Methods ◽  
New Records ◽  
Ground Beetles ◽  
New Information ◽  
First Time

Bulgarian carabid fauna is relatively well studied but there are still many species and regions in the country lacking enough research. The present paper aims at complementing the data about the distribution of the carabids from the subfamily Trechinae, containing many diverse, interesting and endemic species. Currently, 55 species of Trechini, 118 species of Bembidiini (incl. Tachyina), and 13 species of Pogonini are known in Bulgaria. This study gives new information and new records on 41 Trechinae species and 17 zoogeographical regions and subregions. The material was collected in the period from 1979 to 2020 through different sampling methods. There are 20 species recorded for the first time in different regions. Two species are reported for the second time in the regions where they were currently collected. Seventeen species haven’t been reported for more than 20 years from the Boboshevo-Simitli valley, Sandanski-Petrich valley, Rila Mts., Pirin Mts., and Slavyanka Mts., and are now discovered there again.

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