scholarly journals A Morphological and Histological Investigation of Imperfect Lungfish Fin Regeneration

2021 ◽  
Vol 9 ◽  
Author(s):  
Vivien Bothe ◽  
Igor Schneider ◽  
Nadia B. Fröbisch
Keyword(s):  
Tissue Regeneration ◽  
Molecular Mechanisms ◽  
Limb Regeneration ◽  
Body Parts ◽  
Serial Sections ◽  
Fin Regeneration ◽  
X Ray ◽  
The Past ◽  
Great Progress ◽  
Made In

Regeneration, the replacement of body parts in a living animal, has excited scientists for centuries and our knowledge of vertebrate appendage regeneration has increased significantly over the past decades. While the ability of amniotes to regenerate body parts is very limited, members of other vertebrate clades have been shown to have rather high regenerative capacities. Among tetrapods (four-limbed vertebrates), only salamanders show unparalleled capacities of epimorphic tissue regeneration including replacement of organ and body parts in an apparently perfect fashion. The closest living relatives of Tetrapoda, the lungfish, show regenerative abilities that are comparable to those of salamanders and recent studies suggest that these high regenerative capacities may indeed be ancestral for bony fish (osteichthyans) including tetrapods. While great progress has been made in recent years in understanding the cellular and molecular mechanisms deployed during appendage regeneration, comparatively few studies have investigated gross morphological and histological features of regenerated fins and limbs. Likewise, rather little is known about how fin regeneration compares morphologically to salamander limb regeneration. In this study, we investigated the morphology and histology of regenerated fins in all three modern lungfish families. Data from histological serial sections, 3D reconstructions, and x-ray microtomography scans were analyzed to assess morphological features, quality and pathologies in lungfish fin regenerates. We found several anomalies resulting from imperfect regeneration in regenerated fins in all investigated lungfish species, including fusion of skeletal elements, additional or fewer elements, and distal branching. The similarity of patterns in regeneration abnormalities compared to salamander limb regeneration lends further support to the hypothesis that high regenerative capacities are plesiomorphic for sarcopterygians.

Formation, translocation and resolution of Holliday junctions during homologous genetic recombination

1995 ◽  
Vol 347 (1319) ◽  
pp. 21-25 ◽  
Keyword(s):  
Molecular Mechanisms ◽  
Genetic Recombination ◽  
Holliday Junctions ◽  
The Novel ◽  
E Coli ◽  
The Past ◽  
Endonucleolytic Cleavage ◽  
Insight Into ◽  
Made In

Over the past three or four years, great strides have been made in our understanding of the proteins involved in recombination and the mechanisms by which recombinant molecules are formed. This review summarizes our current understanding of the process by focusing on recent studies of proteins involved in the later steps of recombination in bacteria. In particular, biochemical investigation of the in vitro properties of the E. coli RuvA, RuvB and RuvC proteins have provided our first insight into the novel molecular mechanisms by which Holliday junctions are moved along DNA and then resolved by endonucleolytic cleavage.

An Integrative Approach to the Assessment and Treatment of Inflammatory Conditions

2017 ◽  
Author(s):  
Mark Liponis ◽  
Bettina Martin
Keyword(s):  
Integrative Approach ◽  
The Past ◽  
Inflammatory Conditions ◽  
Improved Outcomes ◽  
Targeted Treatments ◽  
Great Progress ◽  
Assessment And Treatment ◽  
The Many ◽  
Made In

The past two decades have seen great progress in recognizing the importance of inflammation in medicine. Increased focus on inflammation in both prevention and treatment has improved outcomes and quality of life in chronic diseases. Science has improved our understanding of inflammation’s many causes and effects on health, and many advances have been made in the availability of targeted therapeutic options for treating inflammation. This chapter gives an overview of recognizing the many causes of inflammation, its many targeted treatments strategies, and the questions that still surround it. It discusses several integrative approaches to reducing inflammation, including exercise, diet, and different strategies for managing sleep, mood, and stress, such as meditation and massage.

scholarly journals Comparative iTRAQ proteomics revealed proteins associated with lobed fin regeneration in Bichirs

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Suxiang Lu ◽  
Qian Xiong ◽  
Kang Du ◽  
Xiaoni Gan ◽  
Xuzhen Wang ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Multiple Reaction Monitoring ◽  
Limb Regeneration ◽  
Differentially Expressed ◽  
Receptor Interaction ◽  
Differentially Expressed Proteins ◽  
Absolute Quantitation ◽  
Bioinformatics Analyses ◽  
Fin Regeneration ◽  
Early Stages

Abstract Background Polypterus senegalus can fully regenerate its pectoral lobed fins, including a complex endoskeleton, with remarkable precision. However, despite the enormous potential of this species for use in medical research, its regeneration mechanisms remain largely unknown. Methods To identify the differentially expressed proteins (DEPs) during the early stages of lobed fin regeneration in P. senegalus, we performed a differential proteomic analysis using isobaric tag for relative and absolute quantitation (iTRAQ) approach based quantitative proteome from the pectoral lobed fins at 3 time points. Furthermore, we validated the changes in protein expression with multiple-reaction monitoring (MRM) analysis. Results The experiment yielded a total of 3177 proteins and 15,091 unique peptides including 1006 non-redundant (nr) DEPs. Of these, 592 were upregulated while 349 were downregulated after lobed fin amputation when compared to the original tissue. Bioinformatics analyses showed that the DEPs were mainly associated with Ribosome and RNA transport, metabolic, ECM-receptor interaction, Golgi and endoplasmic reticulum, DNA replication, and Regulation of actin cytoskeleton. Conclusions To our knowledge, this is the first proteomic research to investigate alterations in protein levels and affected pathways in bichirs’ lobe-fin/limb regeneration. In addition, our study demonstrated a highly dynamic regulation during lobed fin regeneration in P. senegalus. These results not only provide a comprehensive dataset on differentially expressed proteins during the early stages of lobe-fin/limb regeneration but also advance our understanding of the molecular mechanisms underlying lobe-fin/limb regeneration.

scholarly journals Nematostella vectensis, an Emerging Model for Deciphering the Molecular and Cellular Mechanisms Underlying Whole-Body Regeneration

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2692
Author(s):  
Eric Röttinger
Keyword(s):  
Molecular Mechanisms ◽  
Marine Invertebrates ◽  
Marine Organism ◽  
Whole Body ◽  
Nematostella Vectensis ◽  
Body Parts ◽  
Cellular Mechanisms ◽  
Regenerative Capacity ◽  
The Past ◽  
Insight Into

The capacity to regenerate lost or injured body parts is a widespread feature within metazoans and has intrigued scientists for centuries. One of the most extreme types of regeneration is the so-called whole body regenerative capacity, which enables regeneration of fully functional organisms from isolated body parts. While not exclusive to this habitat, whole body regeneration is widespread in aquatic/marine invertebrates. Over the past decade, new whole-body research models have emerged that complement the historical models Hydra and planarians. Among these, the sea anemone Nematostella vectensis has attracted increasing interest in regard to deciphering the cellular and molecular mechanisms underlying the whole-body regeneration process. This manuscript will present an overview of the biological features of this anthozoan cnidarian as well as the available tools and resources that have been developed by the scientific community studying Nematostella. I will further review our current understanding of the cellular and molecular mechanisms underlying whole-body regeneration in this marine organism, with emphasis on how comparing embryonic development and regeneration in the same organism provides insight into regeneration specific elements.

scholarly journals Recent advances in the tandem annulation of 1,3-enynes to functionalized pyridine and pyrrole derivatives

2021 ◽  
Vol 17 ◽  
pp. 2462-2476
Author(s):  
Yi Liu ◽  
Puying Luo ◽  
Yang Fu ◽  
Tianxin Hao ◽  
Xuan Liu ◽  
...  
Keyword(s):  
Reaction Mechanisms ◽  
Structural Motifs ◽  
Pyrrole Derivatives ◽  
The Past ◽  
Recent Advances ◽  
Functionalized Pyridine ◽  
Great Progress ◽  
Made In

Great progress has been made in the tandem annulation of enynes in the past few years. This review only presents the corresponding reactions of 1,3-enyne structural motifs to provide the functionalized pyridine and pyrrole derivatives. The functionalization reactions cover iodination, bromination, trifluoromethylation, azidation, carbonylation, arylation, alkylation, selenylation, sulfenylation, amidation, esterification, and hydroxylation. We also briefly introduce the applications of the products and the reaction mechanisms for the synthesis of corresponding N-heterocycles.

scholarly journals FIBROUS DYSPLASIA OF BONES.

2020 ◽  
pp. 1-3
Author(s):  
M. Darrsana ◽  
Venkatachalam. K ◽  
Ampalaya Manu R ◽  
Haemanath P
Keyword(s):  
Fibrous Dysplasia ◽  
Bone Remodelling ◽  
X Rays ◽  
Endocrine Dysfunction ◽  
X Ray ◽  
The Past ◽  
Café Au Lait Spots ◽  
Gs Alpha ◽  
Topping Off ◽  
Made In

Fibrous dysplasia is an ailment , that can include , one or a few bones and is portrayed by bone deformations, pain and fractures, arising due to bone weakening. A few patients can also present with endocrine dysfunction ( precocious puberty) and cutaneous cafe '- au - lait spots.[1] Determination depends on X-ray assessment. Anticipation is to be surveyed with X-rays and markers of bone remodelling. A few newer comprehensions , of the patho - physiology have been made in the past I0 years. It is presently perceived that fibrous dysplasia is brought about , by a physical initiating transformation of the Gs alpha subunits , of the protein G, bringing about an expanded cAMP fixation and in this way, brings about anomalies of osteoblasts separation, and then subsequently these osteoblasts, creates abnormal bone. There is also an expansion in interleukin-6-initiated osteoclastic bone resorption, which forms the basis of reasoning, for treating these patients with bisphosphonates. In the previous 10 years, the bisphosphonate pamidronate has been utilized by imbuement for fibrous dysplasia (two courses for each year), with great outcomes regarding pain and, in about half of patients, the topping off of osteolytic sores.[2]

scholarly journals Binary Stucture of Accreting Neutron Stars

1998 ◽  
Vol 188 ◽  
pp. 105-106
Author(s):  
D.A. Leahy
Keyword(s):  
Neutron Stars ◽  
Spectral Resolution ◽  
Relevant Literature ◽  
Short Paper ◽  
X Rays ◽  
X Ray ◽  
The Past ◽  
Great Progress ◽  
Satellite Missions ◽  
X Ray Binaries

The study of X-ray binaries has made great progress with the advent in the past few years of a number of very capable X-ray astronomy missions. These are reviewed, for example, by Bradt et al 1992, and a set of recent relevant papers in Makino and Mitsuda, 1997. For example, ASCA has allowed a significant increase in sensitivity and spectral resolution in 0.5-10 keV X-rays (Tanaka et al 1994). Many recent Compton/GRO results on X-ray binaries are reviewed in the proceedings of the Second Compton Symposium (Fichtel et al 1994). Another source of recent results from analysis of data from several satellite missions is the proceedings of the Evolution of X-ray Binaries (Holt & Day, 1994). In this short paper, the emphasis is on guiding the reader to some relevant literature.

scholarly journals Khan Academy Videos in Chinese: A Case Study in OER Revision

2017 ◽  
Vol 18 (5) ◽  
Author(s):  
Allen Rao ◽  
John Hilton III ◽  
Sarah Harper
Keyword(s):  
Open Educational Resources ◽  
Educational Resources ◽  
The Past ◽  
Local Contexts ◽  
Great Progress ◽  
Open Courses ◽  
Khan Academy ◽  
Made In

<p class="3">Over the past decade, great progress has been made in improving the quality and availability of Open Educational Resources (OER). OER proponents often discuss the ability for users to revise and remix OER to make them more suitable for local contexts; however, much OER goes unmodified. This note from the field examines the efforts of NetEase Online Open Courses, a Chinese organization, to take more than two thousand Khan Academy videos and translate them into Chinese. We provide background on this initiative and also analyze site metrics to determine what type of use these derivative OER have received.</p>

Presidential Address

1913 ◽  
Vol 7 ◽  
pp. 1-24
Author(s):  
Archdeacon W. Cunningham
Keyword(s):  
Presidential Address ◽  
Young Men ◽  
British History ◽  
English History ◽  
Richard Iii ◽  
The Past ◽  
Great Progress ◽  
Made In

During the past year the Society has sustained one loss that overshadows all others. It is not for me to attempt to appreciate the value of the substantial contributions to the published sources of English history to which Mr. James Gairdner devoted himself so assiduously; I can only attempt to express the feeling which many of us here must share on the loss of our friend. I well remember the intense interest with which I read his ‘Life of Richard III.’ when it was first published in 1878, and the pleasure which I felt many years after in coming into contact with a man whom I admired so much. His constant kindliness and readiness to interest himself in and encourage the work of young men are not things to be readily forgotten. The chronicling of the blanks left in the roll of our officials and members is the saddest part of a President's duty. In my first address I expressed our sense of loss sustained through the death of Dr. Charles Gross; at this distance of time we can see more clearly than was possible four years ago how fruitful his work was. This year great progress has been made in the attempt to carry on the Bibliography of British History which he began, and during the last few weeks I have been impressed anew with the freshness and thoroughness of his studies, as I have been trying to look into and amplify the argument of his essay on Scottish Municipal History.

New developments in the theory and interpretation of X-ray spectra based on fast parallel calculations

2002 ◽  
Vol 10 (1) ◽  
pp. 43-45 ◽  
Author(s):  
J. J. Rehr ◽  
A. L. Ankudinov
Keyword(s):  
Ab Initio ◽  
Structural Biology ◽  
Significant Progress ◽  
Edge Structure ◽  
New Developments ◽  
X Ray ◽  
The Past ◽  
Current State ◽  
X Ray Absorption ◽  
Made In

There has been dramatic progress over the past decade both in theory and inab initiocalculations of X-ray absorption fine structure. Significant progress has also been made in understanding X-ray absorption near-edge structure (XANES). This contribution briefly reviews the developments in this field leading up to the current state. One of the key advances has been the development of severalab initiocodes such asFEFF, which permit an interpretation of the spectra in terms of geometrical and electronic properties of a material. Despite this progress, XANES calculations have remained challenging both to compute and to interpret. However, recent advances based on parallel Lanczos multiple-scattering algorithms have led to speed increases of typically two orders of magnitude, making fast calculations practicable. Improvements in the interpretation of near-edge structure have also been made. It is suggested that these developments can be advantageous in structural biology,e.g.in post-genomics studies of metalloproteins.

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