Mars and Earth as Twins

2020 ◽  
pp. 35-45
Author(s):  
David A. Weintraub
Keyword(s):  
Eighteenth Century ◽  
Physical Properties ◽  
Black Spot ◽  
Dark Spot ◽  
Amateur Astronomer

This chapter details how astronomers fell in love with Mars during the very earliest years of the age of telescopes because it could appear quite large when viewed through the lens, as it is closer to Earth than all other planets. It discusses the astronomers that gained knowledge about the physical properties of Mars by the end of the eighteenth century that were convinced that Earth and Mars could be thought of as twins. It also recounts the first claimed telescopic detection of a black spot on Mars' surface in 1636 and again in 1638 by amateur astronomer Francesco Fontana. The chapter explains how Fontana's dark spot drew the attention of other astronomers to Mars as an object of interest with the potential to show observers something other than a bland, featureless disk. It refers to astronomers armed with telescopes who scould peer through the depths of space and unravel the mysteries of the red planet.

scholarly journals Towards an Archaeology of Everyday Aesthetics

2017 ◽  
Vol 27 (4) ◽  
pp. 607-616 ◽  
Author(s):  
Robin Skeates
Keyword(s):  
Eighteenth Century ◽  
Physical Properties ◽  
Modern Art ◽  
Qualitative Evaluation ◽  
Philosophical Study ◽  
Everyday Aesthetics ◽  
Anthropological Approach ◽  
The Senses ◽  
Greek Art

The concept of aesthetics has long been marginalized in archaeology. It was originally formulated in the eighteenth century as part of an appreciation of Greek art and was fundamentally concerned with appreciating a quasi-universal idea of beauty; and as archaeologists and anthropologists recognized the distortion created by applying it to material from non-Western and pre-modern art, it fell into disfavour. An alternative anthropological approach pioneered by Howard Morphy regards aesthetics as the study of the affects of the physical properties of objects on the senses and the qualitative evaluation of those properties; this converges with the emerging philosophical study of ‘everyday aesthetics’. This article explores how archaeologists could apply these concepts, particularly through a study of Maltese Neolithic everyday aesthetics.

Acanthopagrus taiwanensis, a new sparid fish (Perciformes), with comparisons to Acanthopagrus berda (Forsskål, 1775) and other nominal species of Acanthopagrus

Zootaxa ◽  
2006 ◽  
Vol 1202 (1) ◽  
pp. 1 ◽  
Author(s):  
YUKIO IWATSUKI ◽  
KENT E. CARPENTER
Keyword(s):  
Posterior Part ◽  
Black Spot ◽  
Dark Spot ◽  
Nominal Species ◽  
Older Individuals ◽  
Pectoral Fins ◽  
Molar Teeth ◽  
Southwestern Taiwan ◽  
Upper Jaw ◽  
Ventral Edge

A new sparid species, Acanthopagrus taiwanensis, is described on the basis of six specimens that were previously misidentified as A. berda (Forsskål, 1775), collected from Tung-kang, southwestern Taiwan. Acanthopagrus taiwanensis and A. berda are similar in overall appearance, both with deep bodies. However, A. taiwanensis differs from the latter in having a more rounded body, broadly rounded anteriormost head squamation with around 10 somewhat smaller scales anteriorly, 3 or 4 cheek scale rows, thin upper and lower lips, older individuals with a ridge on dorsal profile in front of eye and upper profile of head evenly convex, head and body black with sharply contrasting white area ventrally, a dark spot at upper base of pectoral fins, and flat molar teeth. In contrast, A. berda has a deeper body, broadly rounded anteriormost head squamation with around 20 small scales anteriorly, 5 or 6 cheek scale rows, thick upper and lower lips, larger individuals with a weak ridge in profile in front of eye and concave snout profile, head and body silvery gray, no black spot at upper base of pectoral fins and somewhat pointed molar teeth. Older individuals of A. berda also develop a strong concavity of the ventral edge of the first two infraorbitals above the posterior part of upper jaw, while the edge is relatively straight or weakly concave in A. taiwanensis. We discuss the nominal species that have been placed in synonymy with A. berda and contrast A. taiwanensis with similar congeners.

scholarly journals Genome Sequence of the Necrotrophic Plant Pathogen Alternaria brassicicola Abra43

2018 ◽  
Vol 6 (6) ◽  
pp. e01559-17 ◽  
Author(s):  
Elodie Belmas ◽  
Martial Briand ◽  
Anthony Kwasiborski ◽  
Justine Colou ◽  
Guillaume N’Guyen ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Plant Pathogen ◽  
Draft Genome ◽  
Black Spot ◽  
Fungal Diseases ◽  
Alternaria Brassicicola ◽  
Draft Genome Sequence ◽  
Dark Spot ◽  
Spot Disease ◽  
Black Spot Disease

ABSTRACT Alternaria brassicicola causes dark spot (or black spot) disease, which is one of the most common and destructive fungal diseases of Brassicaceae spp. worldwide. Here, we report the draft genome sequence of strain Abra43. The assembly comprises 29 scaffolds, with an N50 value of 2.1 Mb. The assembled genome was 31,036,461 bp in length, with a G+C content of 50.85%.

The Photometric Properties of the Ap Stars

1976 ◽  
Vol 32 ◽  
pp. 365-377 ◽  
Author(s):  
B. Hauck
Keyword(s):  
Physical Properties ◽  
Ap Stars

The Ap stars are numerous - the photometric systems tool It would be very tedious to review in detail all that which is in the literature concerning the photometry of the Ap stars. In my opinion it is necessary to examine the problem of the photometric properties of the Ap stars by considering first of all the possibility of deriving some physical properties for the Ap stars, or of detecting new ones. My talk today is prepared in this spirit. The classification by means of photoelectric photometric systems is at the present time very well established for many systems, such as UBV, uvbyβ, Vilnius, Geneva and DDO systems. Details and methods of classification can be found in Golay (1974) or in the proceedings of the Albany Colloquium edited by Philip and Hayes (1975).

The Infection of Cells by Bullet-Shaped Viruses

1969 ◽  
Vol 27 ◽  
pp. 372-373
Author(s):  
Frederick A. Murphy ◽  
Alyne K. Harrison ◽  
Sylvia G. Whitfield
Keyword(s):  
Electron Microscopy ◽  
Physical Properties ◽  
Host Cell ◽  
Thin Section ◽  
Cultured Cells ◽  
Cell Infection ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Section Electron Microscopy

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.

Transmission electron microscopy of composite materials

1988 ◽  
Vol 46 ◽  
pp. 1012-1015
Author(s):  
K.P.D. Lagerlof
Keyword(s):  
Composite Materials ◽  
Physical Properties ◽  
Structural Defects ◽  
Structural Composites ◽  
Multiphase Materials ◽  
Structural Reinforcement ◽  
Transmission Electron ◽  
Reinforced Fiber ◽  
Particulate Reinforced Composites ◽  
Definition Of

Although most materials contain more than one phase, and thus are multiphase materials, the definition of composite materials is commonly used to describe those materials containing more than one phase deliberately added to obtain certain desired physical properties. Composite materials are often classified according to their application, i.e. structural composites and electronic composites, but may also be classified according to the type of compounds making up the composite, i.e. metal/ceramic, ceramic/ceramie and metal/semiconductor composites. For structural composites it is also common to refer to the type of structural reinforcement; whisker-reinforced, fiber-reinforced, or particulate reinforced composites [1-4].For all types of composite materials, it is of fundamental importance to understand the relationship between the microstructure and the observed physical properties, and it is therefore vital to properly characterize the microstructure. The interfaces separating the different phases comprising the composite are of particular interest to understand. In structural composites the interface is often the weakest part, where fracture will nucleate, and in electronic composites structural defects at or near the interface will affect the critical electronic properties.

A Method for Setting the Clearance Angle

1972 ◽  
Vol 30 ◽  
pp. 388-389
Author(s):  
Michael T. Bucek ◽  
Howard J. Arnott
Keyword(s):  
Experimental Evidence ◽  
Light Source ◽  
Black Spot ◽  
Critical Factor ◽  
Clearance Angle ◽  
Crude Approximation ◽  
Ultrathin Sections

It is believed by the authors, with supporting experimental evidence, that as little as 0.5°, or less, knife clearance angle may be a critical factor in obtaining optimum quality ultrathin sections. The degree increments located on the knife holder provides the investigator with only a crude approximation of the angle at which the holder is set. With the increments displayed on the holder one cannot set the clearance angle precisely and reproducibly. The ability to routinely set this angle precisely and without difficulty would obviously be of great assistance to the operator. A device has been contrived to aid the investigator in precisely setting the clearance angle. This device is relatively simple and is easily constructed. It consists of a light source and an optically flat, front surfaced mirror with a minute black spot in the center. The mirror is affixed to the knife by placing it permanently on top of the knife holder.

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