scholarly journals General characterization of regeneration in Aeolosoma viride

2018 ◽  
Author(s):  
Chiao-Ping Chen ◽  
Sheridan Ke-Wing Fok ◽  
Yu-Wen Hsieh ◽  
Cheng-Yi Chen ◽  
Fei-Man Hsu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Model Organisms ◽  
Regenerative Processes ◽  
Blastema Cell ◽  
Microtubule Inhibitor ◽  
Wide Range ◽  
Highly Correlated ◽  
High Level ◽  
Complete Regeneration

Regeneration has long attracted scientists for its potential to restore lost, damaged or aged tissues and organs. A wide range of studies have conducted on different model organisms on both cellular and molecular levels. Current evidences suggest that a variety of regenerative strategies are developed and used by different species, and their regenerative strategies are highly correlated to their reproductive methods. Our present work focused on the freshwater annelid Aeolosoma viride, which reproduces by paratonic fission and is capable of complete regeneration. We found out that A. viride can regenerate both anterior and posterior end, even with only 3 segments remained. This process is characterized by epimorphosis that involves large amount of cell proliferation which drives the formation of blastema. Cell proliferation and regeneration successful ratio were significantly decreased when treated with microtubule inhibitor taxol or Avi-tubulin dsRNA, which confirmed that cell proliferation served as a key event during regeneration. Together, our data described the regenerative processes of A. viride, which includes high level of cell proliferation and the formation of blastema. Furthermore, our findings demonstrated A. viride as a potential model for the study of regeneration.

A Comparison of Urban with Rural Support Networks: Liverpool and North Wales

1995 ◽  
Vol 15 (1) ◽  
pp. 59-81 ◽  
Author(s):  
G. Clare Wenger
Keyword(s):  
Rural Communities ◽  
Support Networks ◽  
Support Network ◽  
Social Variables ◽  
North Wales ◽  
Care And Support ◽  
Wide Range ◽  
Highly Correlated ◽  
High Level ◽  
The City

AbstractThis paper compares findings on the distribution of support networks in the City of Liverpool and in rural communities in North Wales. It demonstrates that while support network type is highly correlated with a wide range of demographic and social variables in both urban and rural samples, the nature of the relationships are not always comparable. The paper shows how cultural, migration and socio-economic factors interact to affect the formation of different types of support networks. As a result of a more stable elderly population, more old people in Liverpool have network types able to provide a high level of informal care and support.

scholarly journals Cell Proliferation and Cortical Cell Production in Relation to Wool Growth

1979 ◽  
Vol 32 (3) ◽  
pp. 317 ◽  
Author(s):  
Patricia A Wilson ◽  
BF Short
Keyword(s):  
Cell Proliferation ◽  
Nutrient Intake ◽  
Cortical Cell ◽  
Cortical Cells ◽  
Wool Growth ◽  
Wide Range ◽  
High Level ◽  
Relationship Of ◽  
The Relationship ◽  
Germinal Cells

The relationship of wool growth to cell proliferation in the follicle bulb and to the subsequent migration and growth of the fibre cortical cells was investigated in 10 Peppin Merino sheep. These sheep had been maintained on a low, medium or high level of nutrient intake to ensure a wide range in wool growth. The number and mitotic activity of the germinal cells in the follicle bulb were determined after administration of colchicine. Cortical cell size was measured following isolation of the fibre cells by acid-treatment of wool.

scholarly journals Applied Demography In Action: A Case Study of “Population Identification.”

2008 ◽  
Vol 35 (1) ◽  
pp. 133 ◽  
Author(s):  
David A. Swanson
Keyword(s):  
Nuclear Regulatory Commission ◽  
Nuclear Waste Repository ◽  
Graduate Studies ◽  
Wide Range ◽  
The Us ◽  
High Level Nuclear Waste ◽  
Regulatory Commission ◽  
High Level

This case study deals with a problem quite different than the typical one facing most applied demographers. It involves the identification of a “population” using a set of criteria established by a regulatory agency. Specifically, criteria established by the US Nuclear Regulatory Commission for purposes of Site Characterization of the High Level Nuclear Waste Repository proposed for Yucca Mountain, Nevada. Consistent with other recent studies, this one suggests that a wide range of skills may be needed in dealing with problems posed to applied demographers by clients and users in the 21st century. As such, budding applied demographers, especially those nearing completion of their graduate studies, should consider adopting a set of skills beyond traditional demography.

scholarly journals Characterization of the variability in the O+B eclipsing binary HD 165246

2021 ◽  
Vol 503 (1) ◽  
pp. 1124-1137
Author(s):  
C Johnston ◽  
N Aimar ◽  
M Abdul-Masih ◽  
D M Bowman ◽  
T R White ◽  
...  
Keyword(s):  
Binary Solution ◽  
Rotational Frequency ◽  
Primary Component ◽  
Data Set ◽  
Eclipsing Binary ◽  
Photometric Observations ◽  
Wide Range ◽  
Evolutionary Context ◽  
High Level

ABSTRACT O-stars are known to experience a wide range of variability mechanisms originating at both their surface and their near-core regions. Characterization and understanding of this variability and its potential causes are integral for evolutionary calculations. We use a new extensive high-resolution spectroscopic data set to characterize the variability observed in both the spectroscopic and space-based photometric observations of the O+B eclipsing binary HD 165246. We present an updated atmospheric and binary solution for the primary component, involving a high level of microturbulence ($13_{-1.3}^{+1.0}\,$ km s−1) and a mass of $M_1=23.7_{-1.4}^{+1.1}$ M⊙, placing it in a sparsely explored region of the Hertzsprung--Russell diagram. Furthermore, we deduce a rotational frequency of $0.690\pm 0.003\,$d−1 from the combined photometric and line-profile variability, implying that the primary rotates at 40 per cent of its critical Keplerian rotation rate. We discuss the potential explanations for the overall variability observed in this massive binary, and discuss its evolutionary context.

scholarly journals Computational Characterization of Astrophysical Species: The Case of Noble Gas Hydride Cations

2021 ◽  
Vol 9 ◽  
Author(s):  
María Judit Montes de Oca-Estévez ◽  
Rita Prosmiti
Keyword(s):  
Spectroscopic Data ◽  
Noble Gas ◽  
Basis Sets ◽  
Spectroscopic Constants ◽  
Computational Studies ◽  
Future Studies ◽  
Wide Range ◽  
Vibrational Levels ◽  
High Level

Theoretical–computational studies together with recent astronomical observations have shown that under extreme conditions in the interstellar medium (ISM), complexes of noble gases may be formed. Such observations have generated a wide range of possibilities. In order to identify new species containing such atoms, the present study gathers spectroscopic data for noble gas hydride cations, NgH+ (Ng = He, Ne, Ar) from high-level ab initio quantum chemistry computations, aiming to contribute in understanding the chemical bonding and electron sharing in these systems. The interaction potentials are obtained from CCSD(T)/CBS and MRCI+Q calculations using large basis sets, and then employed to compute vibrational levels and molecular spectroscopic constants for all known stable isotopologues of ground state NgH+ cations. Comparisons with previously reported values available are discussed, indicating that the present data could serve as a benchmark for future studies on these systems and on higher-order cationic noble gas hydrides of astrophysical interest.

scholarly journals A TALE of shrimps: Genome-wide survey of homeobox genes in 120 species from diverse crustacean taxa

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 71
Author(s):  
Wai Hoong Chang ◽  
Alvina G. Lai
Keyword(s):  
Homeobox Genes ◽  
Whole Body ◽  
Model Organisms ◽  
Data Sets ◽  
Crop Species ◽  
Physiological Processes ◽  
Genome Wide ◽  
Wide Range ◽  
Identification And Characterization

The homeodomain-containing proteins are an important group of transcription factors found in most eukaryotes including animals, plants and fungi. Homeobox genes are responsible for a wide range of critical developmental and physiological processes, ranging from embryonic development, innate immune homeostasis to whole-body regeneration. With continued fascination on this key class of proteins by developmental and evolutionary biologists, multiple efforts have thus far focused on the identification and characterization of homeobox orthologs from key model organisms in attempts to infer their evolutionary origin and how this underpins the evolution of complex body plans. Despite their importance, the genetic complement of homeobox genes has yet been described in one of the most valuable groups of animals representing economically important food crops. With crustacean aquaculture being a growing industry worldwide, it is clear that systematic and cross-species identification of crustacean homeobox orthologs is necessary in order to harness this genetic circuitry for the improvement of aquaculture sustainability. Using publicly available transcriptome data sets, we identified a total of 4183 putative homeobox genes from 120 crustacean species that include food crop species, such as lobsters, shrimps, crayfish and crabs. Additionally, we identified 717 homeobox orthologs from 6 other non-crustacean arthropods, which include the scorpion, deer tick, mosquitoes and centipede. This high confidence set of homeobox genes will now serve as a key resource to the broader community for future functional and comparative genomics studies.

scholarly journals Purification and characterization of cytosolic and microsomal cyclophilins from maize (Zea mays)

1996 ◽  
Vol 315 (3) ◽  
pp. 965-970 ◽  
Author(s):  
Philip S. SHELDON ◽  
Michael A. VENIS
Keyword(s):  
Cyclosporin A ◽  
Sequence Similarity ◽  
Terminal Sequence ◽  
Purification And Characterization ◽  
Cyclophilin B ◽  
Sds Page ◽  
Wide Range ◽  
Molecular Masses ◽  
High Level

Methods for the purification and separation of peptidyl prolyl cis–trans isomerase (PPI) from cytosolic and microsomal fractions of etiolated maize are described. On SDS/PAGE, the purified preparations appear as single polypeptides with molecular masses of 17.5 kDa and 17.7 kDa respectively. Instead of using immobilized cyclosporin A derivatives as affinity adsorbents, our methods employ conventional techniques enabling purification of the proteins on a much larger scale than previously described. An antiserum raised against the cytosolic PPI recognizes polypeptides of similar molecular mass from a wide range of plant species on an immunoblot. There is virtually no recognition of the microsomal PPI. The cytosolic and microsomal PPIs are inhibited by cyclosporin A (Ki = 6 nM in both cases), indicating that they are cyclophilins. The cytosolic enzyme is inactivated by 5 mM N-ethylmaleimide and 2 mM phenylglyoxal. N-terminal sequencing of the microsomal PPI indicates a high level of sequence similarity with the N-terminal sequence of mature animal s-cyclophilin (cyclophilin B).

scholarly journals Isolation and Biochemical Characterization of Two Novel Metagenome-Derived Esterases

2006 ◽  
Vol 72 (5) ◽  
pp. 3637-3645 ◽  
Author(s):  
C. Elend ◽  
C. Schmeisser ◽  
C. Leggewie ◽  
P. Babiak ◽  
J. D. Carballeira ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Biotechnological Applications ◽  
Temperature Optimum ◽  
Ph Optimum ◽  
Level Of Activity ◽  
Wide Range ◽  
Soil Metagenome ◽  
Ph Range ◽  
High Level

ABSTRACT The metagenomes of uncultured microbial communities are rich sources for novel biocatalysts. In this study, esterase EstA3 was derived from a drinking water metagenome, and esterase EstCE1 was derived from a soil metagenome. Both esterases are approximately 380 amino acids in size and show similarity to β-lactamases, indicating that they belong to family VIII of the lipases/esterases. EstA3 had a temperature optimum at 50�C and a pH optimum at pH 9.0. It was remarkably active and very stable in the presence of solvents and over a wide temperature and pH range. It is active in a multimeric form and displayed a high level of activity against a wide range of substrates including one secondary ester, 7-[3-octylcarboxy-(3-hydroxy-3-methyl-butyloxy)]-coumarin, which is normally unreactive. EstCE1 was active in the monomeric form and had a temperature optimum at 47�C and a pH optimum at pH 10. It exhibited the same level of stability as EstA3 over wide temperature and pH ranges and in the presence of dimethyl sulfoxide, isopropanol, and methanol. EstCE1 was highly enantioselective for (+)-menthylacetate. These enzymes display remarkable characteristics that cannot be related to the original environment from which they were derived. The high level of stability of these enzymes together with their unique substrate specificities make them highly useful for biotechnological applications.

The glycomes of Caenorhabditis elegans and other model organisms

2002 ◽  
Vol 69 ◽  
pp. 117-134 ◽  
Author(s):  
Stuart M. Haslam ◽  
David Gems ◽  
Howard R. Morris ◽  
Anne Dell
Keyword(s):  
Caenorhabditis Elegans ◽  
Current Knowledge ◽  
Structural Data ◽  
Model Organisms ◽  
Entire Genome ◽  
C Elegans ◽  
The Face ◽  
Area Of Concern ◽  
Nematode Worm

There is no doubt that the immense amount of information that is being generated by the initial sequencing and secondary interrogation of various genomes will change the face of glycobiological research. However, a major area of concern is that detailed structural knowledge of the ultimate products of genes that are identified as being involved in glycoconjugate biosynthesis is still limited. This is illustrated clearly by the nematode worm Caenorhabditis elegans, which was the first multicellular organism to have its entire genome sequenced. To date, only limited structural data on the glycosylated molecules of this organism have been reported. Our laboratory is addressing this problem by performing detailed MS structural characterization of the N-linked glycans of C. elegans; high-mannose structures dominate, with only minor amounts of complex-type structures. Novel, highly fucosylated truncated structures are also present which are difucosylated on the proximal N-acetylglucosamine of the chitobiose core as well as containing unusual Fucα1–2Gal1–2Man as peripheral structures. The implications of these results in terms of the identification of ligands for genomically predicted lectins and potential glycosyltransferases are discussed in this chapter. Current knowledge on the glycomes of other model organisms such as Dictyostelium discoideum, Saccharomyces cerevisiae and Drosophila melanogaster is also discussed briefly.

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