The early origin of feathers

Author(s):  
Michael Benton

<p>Feathers are a diagnostic character of birds, and yet new fossils show they likely originated more than 100 million years before the first birds. In fact, feathers probably occurred in all dinosaur groups, and in their cousins, the pterosaurs, as we showed in 2019. This finding confirms current knowledge of the genomic regulation of feather development. Our work stems from ten years of collaboration with Chinese colleagues, during which we set ourselves the taks of understanding fossil feathers. Our first discovery was to answer the question, ‘Will we ever know the colour of dinosaurs?’. In 2010, we were able to announce the first objective evidence for colour in a dinosaur. Using ultrastructural studies of fossil feathers, we identified melanosomes for the first time in dinosaur feathers, and these demonstrated that Sinosauropteryx had ginger and white rings down its tail. Studies of other dinosaurs identified patterns of black, white, grey, brown, and ginger. This is part of a new wave in palaeobiology where we apply objective approaches to provide testable hypotheses, once thought impossible in the historical sciences.</p>

2021 ◽  
Author(s):  
Michael Benton

<p>Feathers are a diagnostic character of birds, and yet new fossils show they likely originated more than 100 million years before the first birds. In fact, feathers probably occurred in all dinosaur groups, and in their cousins, the pterosaurs, as we showed in 2019. This finding confirms current knowledge of the genomic regulation of feather development. Our work stems from ten years of collaboration with Chinese colleagues, during which we set ourselves the task of understanding fossil feathers. Our first discovery was to answer the question, ‘Will we ever know the colour of dinosaurs?’. In 2010, we were able to announce the first objective evidence for colour in a dinosaur. Using ultrastructural studies of fossil feathers, we identified melanosomes for the first time in dinosaur feathers, and these demonstrated that Sinosauropteryx had ginger and white rings down its tail. Studies of other dinosaurs identified patterns of black, white, grey, brown, and ginger. This is part of a new wave in Palaeobiology where we apply objective approaches to provide testable hypotheses, once thought impossible in the historical sciences.</p><p> </p><p>Benton, M.J., Dhouailly, D., Jiang, B.Y., and McNamara, M. 2019. The early origin of feathers. Trends in Ecology & Evolution 34, 856-869 (doi: 10.1016/j.tree.2019.04.018).</p><p>https://dinocolour.blogs.bristol.ac.uk/</p><p>https://dinosaurs.blogs.bristol.ac.uk/</p>


Author(s):  
Mohamad Hossein Pourhanifeh ◽  
Kazem Abbaszadeh-Goudarzi ◽  
Mohammad Goodarzi ◽  
Sara G.M. Piccirillo ◽  
Alimohammad Shafiee ◽  
...  

: Melanoma is the most life-threatening and aggressive class of skin malignancies. The incidence of melanoma has steadily increased. Metastatic melanoma is greatly resistant to standard anti-melanomatreatments such as chemotherapy, and 5-year survival rate of cases with melanoma who have metastatic form of disease is less than 10%. The contributing role of apoptosis, angiogenesis and autophagy in the pathophysiology of melanoma has been previously demonstrated. Thus, it is extremely urgent to search for complementary therapeutic approachesthat couldenhance the quality of life of subjects and reduce treatment resistance and adverse effects. Resveratrol, known as a polyphenol component present in grapes and some plants, has anti-cancer properties due to its function as an apoptosis inducer in tumor cells, and anti-angiogenic agent to prevent metastasis. However, more clinical trials should be conducted to prove resveratrol efficacy. : Herein, for first time, we summarize current knowledge of anti-cancerous activities of resveratrol in melanoma.


1973 ◽  
Vol 19 (8) ◽  
pp. 887-894
Author(s):  
Linda Poffenroth ◽  
J. W. Costerton ◽  
Nonna Kordová ◽  
John C. Wilt

Electron microscopic examination of a semipurified Chlamydia psittaci 6BC strain attenuated in chick embryo yolk sac revealed for the first time two morphologically distinct small elementary bodies which differ both in the ultrastructure of their surface layers and in their buoyant densities in sucrose gradients. Also, the morphology of the surface layers of the larger reticulate forms in cell-free systems is described for the first time. Many points of difference between the surface envelopes and internal structure of chlamydial particles and those of Gram-negative bacteria are discussed.


2016 ◽  
Vol 39 (5) ◽  
pp. 1977-2000 ◽  
Author(s):  
Etheresia Pretorius ◽  
Jeanette N. du Plooy ◽  
Janette Bester

Erythrocytes (RBCs) are extremely sensitive cells, and although they do not have nuclei and mitochondria, are important health indicators. This is particularly true because, during inflammation, whether it is systemic or chronic, the haematological system is constantly exposed to circulating inflammatory mediators. RBCs have a highly specialized and organized membrane structure, which interacts and reacts to inflammatory molecule insults, and undergo programmed cell death, similar to apoptosis, known as eryptosis. Over the past years, eryptosis studies have focussed on determining if membrane changes have occurred, particularly whether a phosphatidylserine (PS) flip, Ca2+ leakage into the cell, changes to ceramide and cell shrinkage have occurred. Mostly, flow cytometry is used, but confocal microscopy and ultrastructural studies also confirm eryptosis. Here, we provide a comprehensive overview of eryptosis, where we revisit the biochemical process of the process, review all literature in PUBMED, that is shown under the search word, “eryptosis”, and also discuss current methodologies to determine the presence of eryptosis; included in the discussion of the methodologies, we discuss a pitfalls section for each method. This paper is therefore a comprehensive synopsis of current knowledge of eryptosis and discusses how RBCs may provide an essential in vivo cell model system to study not only inflammation in disease, but also track disease progression and treatment regimes.


2009 ◽  
Vol 43 (1) ◽  
pp. e-15-e-24
Author(s):  
I. Dolinskaya

Formation of Pattern and Diagnostic Instar Features of the Head in Caterpillars from Genus Peridea (Lepidoptera, Notodontidae) Pattern and colouration of caterpillar head of all larval instar of 7 species from genus Peridea Stephens, 1828 are studied. Formation of caterpillar head pattern in ontogenesis is discussed. Diagnostic characters, both specific and larval instars, are recorded for the first time. Key to species according to larval instars is given. Evidently, only larvae of the 1st instar demonstrate different directions in the pattern formation. This characteristic can be used for clearing of taxonomic relations in the genera and on the earliest ontogenetic stages (1st larval instar) only. In the following (2nd-5th) instars, the pattern became more or less of the same type. It depends on stripes shape or colouration only and can serve as good specific diagnostic character. To determine larval instar, both width of the head capsule and head pattern should be taken into account.


Dermatology ◽  
2020 ◽  
pp. 1-12 ◽  
Author(s):  
Giovanni Genovese ◽  
Chiara Moltrasio ◽  
Emilio Berti ◽  
Angelo Valerio Marzano

<b><i>Background:</i></b> Coronavirus disease-19 (COVID-19) is an ongoing global pandemic caused by the “severe acute respiratory syndrome coronavirus 2” (SARS-CoV-2), which was isolated for the first time in Wuhan (China) in December 2019. Common symptoms include fever, cough, fatigue, dyspnea and hypogeusia/hyposmia. Among extrapulmonary signs associated with COVID-19, dermatological manifestations have been increasingly reported in the last few months. <b><i>Summary:</i></b> The polymorphic nature of COVID-19-associated cutaneous manifestations led our group to propose a classification, which distinguishes the following six main clinical patterns: (i) urticarial rash, (ii) confluent erythematous/maculopapular/morbilliform rash, (iii) papulovesicular exanthem, (iv) chilblain-like acral pattern, (v) livedo reticularis/racemosa-like pattern, (vi) purpuric “vasculitic” pattern. This review summarizes the current knowledge on COVID-19-associated cutaneous manifestations, focusing on clinical features and therapeutic management of each category and attempting to give an overview of the hypothesized pathophysiological mechanisms of these conditions.


Zootaxa ◽  
2012 ◽  
Vol 3290 (1) ◽  
pp. 1 ◽  
Author(s):  
LUIS GARCÍA-PRIETO ◽  
JORGE FALCÓN-ORDAZ ◽  
CARMEN GUZMÁN-CORNEJO

In the present work, a total of 339 nominal taxa of helminths (53 trematodes, 46 cestodes, 12 acanthocephalans, 227 nem-atodes, and 1 hirudinean), associated with 136 taxa of wild mammals from Mexico, are listed. Information on hosts, hab-itat, distribution, and records is included; these data come from 242 localities, pertaining to 31 of the 32 Mexican states,and represent the current knowledge on helminth parasites of wild mammals in Mexico. Eighteen taxa of helminths are registered for the first time in Mexico, and 46 new locality records are presented.


Zootaxa ◽  
2009 ◽  
Vol 2135 (1) ◽  
pp. 57-64 ◽  
Author(s):  
MING-YI TIAN ◽  
THIERRY DEUVE

In the present paper the Oriental carabid genus Actenoncus Chaudoir, 1871 is redefined and reviewed for the first time. The absence of a median tooth on the right mandible is no longer considered a diagnostic character of this genus. Orthogonius foersteri Andrewes, 1931 is transferred into Actenoncus (new combination) and a new species is described from Indonesia, A. wallacei, new species. A key to all known species of Actenoncus is also provided.


Zootaxa ◽  
2012 ◽  
Vol 3552 (1) ◽  
pp. 1 ◽  
Author(s):  
BENOIT GUÉNARD ◽  
KATHERINE A. MCCAFFREY ◽  
ANDREA LUCKY ◽  
ROB R. DUNN

We document the distribution of ants present in North Carolina. We revisit the list of North Carolina ants for the first time since 1962, based on literature records, museum collection and new sampling events across the state. Our results show 53 new species records, including 16 exotic and 4 undescribed species, for a total of 192 species found in North Carolina. Based on our current knowledge, North Carolina possesses the highest species diversity of native ants of any state or territory in eastern North America. Here, we discuss some of the biogeographical explanations for this remarkable diversity. In addition to presenting county-level species distributions in North Carolina, we also offer brief comparisons to species lists for surrounding states. By highlighting species expected to occur in North Carolina, but not yet recorded in the state, we hope to encourage new discoveries and increase the general knowledge of the ant fauna of North Carolina.


1990 ◽  
Vol 142 ◽  
pp. 149-157
Author(s):  
Joseph M. Davila

Recent observations have demonstrated that sunspots can absorb significant p-mode wave power, and that this absorption has a well defined wavelength dependence. These observations open, for the first time, the potential to deduce semi-empirically the subsurface structure of sunspots and active regions. Several physical mechanisms have been proposed to explain the absorption. In this paper, the proposed mechanisms are reviewed and their viability in view of the current knowledge of the scattering process is discussed.


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