A surprising discovery

2020 ◽  
pp. 7-11
Author(s):  
Daniel Harlow
Keyword(s):  
Surprising Discovery

Mitochondria: the birth place, battle ground and the site of melatonin metabolism in cells

2019 ◽  
Vol 2 (1) ◽  
pp. 44-66 ◽  
Author(s):  
Dun-Xian Tan ◽  
Russel. J. Reiter
Keyword(s):  
Ischemia Reperfusion ◽  
Surface Membrane ◽  
Strong Association ◽  
Membrane Receptors ◽  
Melatonin Receptors ◽  
Metabolic Enzyme ◽  
Intermembrane Space ◽  
Antitumor Effects ◽  
The Matrix ◽  
Surprising Discovery

     It was a surprising discovery when mitochondria, as the power houses of cells, were also found to synthesize the potent mitochondrial targeted antioxidant, melatonin. The melatonin synthetic enzyme serotonin N-acetyltransferase (SNAT) was found in matrix and also in the intermembrane space of mitochondria. We hypothesize that the melatonin synthesis occurs in the matrix due to substrate (N-acetyl co-enzyme A) availability while the intermembrane space may serve as the recycling pool of SNAT to regulate the melatonin circadian rhythm. Another surprise was that the melatonin membrane receptors, including MT1 and MT2, were also present in mitochondria. The protective effects of melatonin against neuronal injury induced by brain ischemia/reperfusion were proven to be mainly mediated by mitochondrial melatonin receptors rather than the cell surface membrane receptors which is contrary to the classical principle. In addition, melatonin metabolic enzyme has also been identified in the mitochondria. This enzyme can convert melatonin to N-acetylserotonin to strengthen the antitumor effects of melatonin. Thus, mitochondria are the generator, battle ground and metabolic sites of melatonin. The biological significance of the strong association between mitochondria and melatonin should be intensively investigated. 

Mitochondria: the birth place, battle ground and the site of melatonin metabolism in cells

2019 ◽  
Vol 2 (1) ◽  
pp. 44-66 ◽  
Author(s):  
Dun-Xian Tan ◽  
Russel. J. Reiter
Keyword(s):  
Ischemia Reperfusion ◽  
Surface Membrane ◽  
Strong Association ◽  
Membrane Receptors ◽  
Melatonin Receptors ◽  
Metabolic Enzyme ◽  
Intermembrane Space ◽  
Antitumor Effects ◽  
The Matrix ◽  
Surprising Discovery

     It was a surprising discovery when mitochondria, as the power houses of cells, were also found to synthesize the potent mitochondrial targeted antioxidant, melatonin. The melatonin synthetic enzyme serotonin N-acetyltransferase (SNAT) was found in matrix and also in the intermembrane space of mitochondria. We hypothesize that the melatonin synthesis occurs in the matrix due to substrate (N-acetyl co-enzyme A) availability while the intermembrane space may serve as the recycling pool of SNAT to regulate the melatonin circadian rhythm. Another surprise was that the melatonin membrane receptors, including MT1 and MT2, were also present in mitochondria. The protective effects of melatonin against neuronal injury induced by brain ischemia/reperfusion were proven to be mainly mediated by mitochondrial melatonin receptors rather than the cell surface membrane receptors which is contrary to the classical principle. In addition, melatonin metabolic enzyme has also been identified in the mitochondria. This enzyme can convert melatonin to N-acetylserotonin to strengthen the antitumor effects of melatonin. Thus, mitochondria are the generator, battle ground and metabolic sites of melatonin. The biological significance of the strong association between mitochondria and melatonin should be intensively investigated. 

Hominin transition to Upper Pliocene

2017 ◽  
Author(s):  
Francisco J. Ayala ◽  
Camilo J. Cela-Conde
Keyword(s):  
Brain Development ◽  
Late Pleistocene ◽  
Technological Progress ◽  
Homo Sapiens ◽  
Middle Pleistocene ◽  
Evolutionary Significance ◽  
Australopithecus Afarensis ◽  
Phylogenetic Significance ◽  
Homo Neanderthalensis ◽  
Surprising Discovery

This chapter analyzes the transition of the hominins from the Middle Pleistocene to the Late Pleistocene. Two alternative models are explored, the “Multiregional Hypothesis” (MH) and the “Replacement Hypothesis,” and how each model evaluates the existing relationships between the taxa Homo neanderthalensis and Homo sapiens. Next is the investigation of the transitional (or “archaic,” if this grade is taken into account) exemplars found in Europe, Africa, and Asia and their evolutionary significance. In particular, the comparison between H. erectus and H. sapiens in China and Java is investigated, as the main foundation of the MH. The chapter ends with the surprising discovery of Homo floresiensis and its description and interpretations concerning its taxonomic and phylogenetic significance. The correlation between brain development and technological progress is at odds with the attribution of perforators, microblades, and fishing hooks to a hominin with a small cranial volume, similar to that of Australopithecus afarensis.

Creative Process II

2019 ◽  
pp. 117-136
Author(s):  
Stephen A. Crist
Keyword(s):  
Creative Process ◽  
Full Length ◽  
Time Out ◽  
Audio Recordings ◽  
History Of ◽  
Shed Light ◽  
Surprising Discovery ◽  
The Way

Among Dave Brubeck’s personal audio recordings are about two dozen takes of “Take Five,” which preceded the full-length version on Time Out and the shorter single release version. This chapter discusses first the familiar versions from July 1959, and then considers how the Quartet’s efforts at the end of June paved the way for those iconic recordings. A surprising discovery from the original session recordings of “Kathy’s Waltz” and “Strange Meadow Lark” is that both cuts were spliced from supplemental takes. The recording history of “Everybody’s Jumpin’ ” includes the unexpected fact that a portion of the tune originated in 1950, nine years before the Time Out sessions. The chapter also examines the original recordings of “Three to Get Ready” and “Blue Rondo à la Turk,” as well as two tracks that shed light on the origins of “Pick Up Sticks.”

KLEIN–DUNHAM POTENTIAL ENERGY FUNCTIONS IN SIMPLIFIED ANALYTICAL FORM

1960 ◽  
Vol 38 (2) ◽  
pp. 217-230 ◽  
Author(s):  
W. R. Jarmain
Keyword(s):  
Potential Energy ◽  
Equivalent Form ◽  
Analytical Form ◽  
Spectroscopic Constants ◽  
Dissociation Limit ◽  
Energy Functions ◽  
Potential Energy Functions ◽  
Small Correction ◽  
Correction Terms ◽  
Surprising Discovery

A simple formula, based originally on the work of Klein and Rees, is developed for calculating potential energy curves, except near the dissociation limit, for electronic states of diatomic molecules. Classical turning points r1,2 are given as functions of vibrational quantum number (V ≡ ν + 1/2), with coefficients depending on observed spectroscopic constants, in the form[Formula: see text]where[Formula: see text]For most states convergence is rapid, but as a rule more so for heavy molecules than for light molecules. Assuming it to be close to the 'true' potential, such a representation affords a convenient means of assessing the accuracy of the Morse or other empirical potential function. Morse curves have also been fitted by least squares to Klein–Rees turning points.Term-by-term comparison between the inverted Dunham series and an equivalent form of the above has led to the surprising discovery that if Dunham's small correction terms are neglected, Klein and Dunham potentials are mathematically identical. This is contrary to the generally held belief that the two should be used in mutually exclusive regions. In the present form these series exhibit better behavior over a wider range than a series giving potential energy as a function of internuclear separation.

scholarly journals ON GENERA

1876 ◽  
Vol 8 (10) ◽  
pp. 194-198
Author(s):  
Dr. H. Hagen
Keyword(s):  
Considerable Time ◽  
Surprising Discovery

There will hardly be a naturalist who has not spent considerable time to study the questions–What is a genus, and what are generic characters? Indeed, work is nearly impossible without having taken a position with regard to these questions. A full record of the literature, even the most condensed one, would be here out of p1ace, but I have been induced by a recent and most surprising discovery bearing upon this question to make this communication.

The Graptolitic Faunas of the Gotlandian in the Eastern Alps and their Relationships

1934 ◽  
Vol 71 (6) ◽  
pp. 268-275 ◽  
Author(s):  
Franz Heritsch
Keyword(s):  
Rapid Development ◽  
Eastern Alps ◽  
Northern Calcareous Alps ◽  
Carnic Alps ◽  
Northern Calcareous ◽  
Southern Margin ◽  
The Alps ◽  
The University ◽  
The Great War ◽  
Surprising Discovery

The years that followed the Great War saw a rapid development in knowledge of the graptolitic faunas of the Eastern Alps. Professor M. Gortani described many graptolites from the Carnic Alps, and papers from the Geological Department of the University of Graz dealt with the same subject, as well as the distribution of the graptolites over a wider area of the Eastern Alps. Especially noteworthy was the surprising discovery of graptolites in the so-called grauwacke zone of the Alps, which follows the southern margin of the Northern Calcareous Alps. In the grauwacke zone, which consists of Palaeozoic and more ancient strata, more or less metamorphosed, graptolites were found at the following localities, (a) Fieberbrunn in the Tyrol (1), where the zones of Monograptus cyphus to M. turriculatus are found, and the presence of M. priodon indicates that higher zones may occur; (b) environs of Eisenerz in Styria (2), where the zones of M. gregarius to M. griestoniensis are found, as well as the zone of M. nilssoni; (c) Montavon in Vorarl-berg (29), where a badly-preserved specimen of Monograptus, possibly M. priodon, was discovered.

'Fräulein Sprengel' and the Origins of the Golden Dawn: A Surprising Discovery

Aries ◽  
2011 ◽  
Vol 11 (2) ◽  
pp. 249-257
Author(s):  
Christopher McIntosh
Keyword(s):  
Surprising Discovery

scholarly journals A Surprising Discovery of American Pika Sites in the Northwestern Great Basin

2017 ◽  
Vol 77 (2) ◽  
pp. 252-268 ◽  
Author(s):  
Mackenzie R. Jeffress ◽  
K. Jane Van Gunst ◽  
Constance I. Millar
Keyword(s):  
Great Basin ◽  
Surprising Discovery ◽  
American Pika

Where Fossils Dare and Males Matter: combined morphological and molecular analysis untangles the evolutionary history of the spider ant genus Leptomyrmex Mayr (Hymenoptera : Dolichoderinae)

2017 ◽  
Vol 31 (6) ◽  
pp. 765 ◽  
Author(s):  
Phillip Barden ◽  
Brendon Boudinot ◽  
Andrea Lucky
Keyword(s):  
Evolutionary History ◽  
Morphological Evolution ◽  
Sister Group ◽  
Morphological Characters ◽  
Fossil Material ◽  
First Case ◽  
History Of ◽  
The Impact ◽  
Surprising Discovery

The distinctive ant genus Leptomyrmex Mayr, 1862 had been thought to be endemic to Australasia for over 150 years, but enigmatic Neotropical fossils have challenged this view for decades. The present study responds to a recent and surprising discovery of extant Leptomyrmex species in Brazil with a thorough evaluation of the Dominican Republic fossil material, which dates to the Miocene. In the first case study of direct fossil inclusion within Formicidae Latreille, 1809, we incorporated both living and the extinct Leptomyrmex species. Through simultaneous analysis of molecular and morphological characters in both Bayesian and parsimony frameworks, we recovered the fossil taxon as sister-group to extant Leptomyrmex in Brazil while considering the influence of taxonomic and character sampling on inferred hypotheses relating to tree topology, biogeography and morphological evolution. We also identified potential loss of signal in the binning of morphological characters and tested the impact of parameterisation on divergence date estimation. Our results highlight the importance of securing sufficient taxon sampling for extant lineages when incorporating fossils and underscore the utility of diverse character sources in accurate placement of fossil terminals. Specifically, we find that fossil placement in this group is influenced by the inclusion of male-based characters and the newly discovered Neotropical ‘Lazarus taxon’.

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