scholarly journals SOHO comets: 20 years and 3000 objects later

Author(s):  
Karl Battams ◽  
Matthew M. Knight

We present a summary of the more than 3000 sungrazing and near-Sun comets discovered in coronagraph images returned by the Solar and Heliospheric Observatory (SOHO), since its launch in December 1995. We address each of the four main populations of objects observed by SOHO: Kreutz (sungrazing) group, Meyer group, Marsden and Kracht (96P-family) group and non-group comets. Discussions for each group include basic properties, discovery statistics and morphological appearance. In addition to updating the community on the status of the discoveries by SOHO, we also show that the rate of discovery of Kreutz sungrazers has probably remained static since approximately 2003 and we report on the first likely fragmentation pair observed within the Meyer group. This article is part of the themed issue ‘Cometary science after Rosetta’.

Zootaxa ◽  
2010 ◽  
Vol 2400 (1) ◽  
pp. 66 ◽  
Author(s):  
D. J. WILLIAMS ◽  
P. J. GULLAN

Since Cockerell (1905) erected the family-group name Pseudococcini, the name has become widely used for all mealybugs. Lobdell (1930) raised the status of the group to family level as the Pseudococcidae, but it was not until Borchsenius (1949) and Ferris (1950) accepted the family level that the rank of Pseudococcidae became more widely accepted within the superfamily Coccoidea. Various tribes and subtribes have been introduced without any reliable classification of the family.


Zootaxa ◽  
2015 ◽  
Vol 3919 (1) ◽  
pp. 111 ◽  
Author(s):  
IAN M. SMITH ◽  
DAVID R. COOK ◽  
REINHARD GERECKE

A number of changes to the status of genus group names in water mites are proposed to foster a more consistent and phylogenetically defensible approach to the ranking of taxa at this level of the classification. The water mite taxa Acercopsis Viets, 1926 (Pionidae: Tiphyinae), Madawaska Habeeb, 1954 (Pionidae: Foreliinae), Brachypodopsis Piersig, 1903, Cubanaxonopsis Orghidan & Gruia, 1981, Hexaxonopsis Viets, 1926, Paraxonopsis Motaş & Tanasachi, 1947, Vicinaxonopsis Cook, 1974, Parabrachypoda Viets, 1929, and Ocybrachypoda Cook, 1974 (Aturidae: Axonopsinae), Ameribrachypoda Smith, 1991 (Aturidae: Aturinae), and Allomideopsis Smith, 1990 (Nudomideopsidae) are elevated in rank from subgenera to full genera to reflect current knowledge of their species diversity, morphological distinctness, relationships and apparent age. In light of the above changes in the subfamily Axonopsinae, the subgenera Kalobrachypoda Viets, 1929 and Navinaxonopsis Cook, 1967 are transferred from the genus Axonopsis to the genus Brachypodopsis, the subgenus Plesiobrachypoda Viets, 1942 is transferred from the genus Axonopsis to the genus Hexaxonopsis, and the species formerly placed in the subgenus Hemibrachypoda Viets, 1937 are transferred from the genus Brachypoda to the genus Parabrachypoda Viets, 1929, and Hemibrachypoda is placed in synonymy with Parabrachypoda. The family group taxa to which all of these genera belong are reviewed to provide context for the proposed changes. 


2009 ◽  
Vol 54 (1) ◽  
Author(s):  
Stephen Bullard ◽  
Kirsten Jensen ◽  
Robin Overstreet

AbstractThe family-group name for the “fish blood flukes” is unstable, with both “Aporocotylidae Odhner, 1912” and “Sanguinicolidae von Graff, 1907” in use for the single family. Although “Sanguinicolidae von Graff, 1907” (or. Graff, 1907.) has been a widely-accepted family-group name for the fish blood flukes subsequent to Yamaguti’s 1954 and 1958 synoptical publications (“Systema Helminthum”), a critical examination of the relevant literature, much of it published in German during 1900 through 1926, reveals that “Aporocotylidae Odhner, 1912” is the earliest available family-group name for these flukes. The name Aporocotylidae, moreover, was in wide usage by alpha taxonomists before 1954 and by several authors between 1954 and the present time. We speculate that the recent long-standing uncertainty about the earliest available family-group name primarily stems from the (1) logistics of Ludwig von Graff’s tome published in 1904–1908, (2) bibliographic confusion between that work and another Graff work published in 1907 (both of which treat Sanguinicola but not Aporocotyle), (3) initial ambiguity regarding the phylogenetic relatedness of the first four aporocotylid species that were named, (4) lack of consensus on the status of Aporocotylidae and Sanguinicolidae and the genera included within them, and (5) misleading application of. Graff, 1907. to Sanguinicolidae by Poche in 1926, Fuhrmann in 1928, Yamaguti in 1954 and 1958, and subsequent review articles that treated fish blood flukes. Under the International Code of Zoological Nomenclature (ICZN, Article 8.3), “Sanguinicolidae” was not made available by Graff because he disclaimed the name in the same, and only, work wherein he used the name (ICZN, Article 8.3). Sanguinicolidae was first made available in 1926 by Poche, who referenced Graff’s 1907 work. Hence, “Poche, 1926” comprises the correct authority and date for that family-group name, not “von Graff, 1907” or “Graff, 1907”. Since we presently accept only a single family for all fish blood flukes and abide by the Principal of Priority (ICZN, Article 23), we herein regard Sanguinicolidae Poche, 1926 as a junior subjective synonym of Aporocotylidae Odhner, 1912.


Author(s):  
L.J. Chen ◽  
Y.F. Hsieh

One measure of the maturity of a device technology is the ease and reliability of applying contact metallurgy. Compared to metal contact of silicon, the status of GaAs metallization is still at its primitive stage. With the advent of GaAs MESFET and integrated circuits, very stringent requirements were placed on their metal contacts. During the past few years, extensive researches have been conducted in the area of Au-Ge-Ni in order to lower contact resistances and improve uniformity. In this paper, we report the results of TEM study of interfacial reactions between Ni and GaAs as part of the attempt to understand the role of nickel in Au-Ge-Ni contact of GaAs.N-type, Si-doped, (001) oriented GaAs wafers, 15 mil in thickness, were grown by gradient-freeze method. Nickel thin films, 300Å in thickness, were e-gun deposited on GaAs wafers. The samples were then annealed in dry N2 in a 3-zone diffusion furnace at temperatures 200°C - 600°C for 5-180 minutes. Thin foils for TEM examinations were prepared by chemical polishing from the GaA.s side. TEM investigations were performed with JE0L- 100B and JE0L-200CX electron microscopes.


Author(s):  
Patrick Echlin

A number of papers have appeared recently which purport to have carried out x-ray microanalysis on fully frozen hydrated samples. It is important to establish reliable criteria to be certain that a sample is in a fully hydrated state. The morphological appearance of the sample is an obvious parameter because fully hydrated samples lack the detailed structure seen in their freeze dried counterparts. The electron scattering by ice within a frozen-hydrated section and from the surface of a frozen-hydrated fracture face obscures cellular detail. (Fig. 1G and 1H.) However, the morphological appearance alone can be quite deceptive for as Figures 1E and 1F show, parts of frozen-dried samples may also have the poor morphology normally associated with fully hydrated samples. It is only when one examines the x-ray spectra that an assurance can be given that the sample is fully hydrated.


Author(s):  
Frank J. Longo

Measurement of the egg's electrical activity, the fertilization potential or the activation current (in voltage clamped eggs), provides a means of detecting the earliest perceivable response of the egg to the fertilizing sperm. By using the electrical physiological record as a “real time” indicator of the instant of electrical continuity between the gametes, eggs can be inseminated with sperm at lower, more physiological densities, thereby assuring that only one sperm interacts with the egg. Integrating techniques of intracellular electrophysiological recording, video-imaging, and electron microscopy, we are able to identify the fertilizing sperm precisely and correlate the status of gamete organelles with the first indication (fertilization potential/activation current) of the egg's response to the attached sperm. Hence, this integrated system provides improved temporal and spatial resolution of morphological changes at the site of gamete interaction, under a variety of experimental conditions. Using these integrated techniques, we have investigated when sperm-egg plasma membrane fusion occurs in sea urchins with respect to the onset of the egg's change in electrical activity.


2000 ◽  
Vol 64 (11) ◽  
pp. 772-774 ◽  
Author(s):  
JG Odom ◽  
PL Beemsterboer ◽  
TD Pate ◽  
NK Haden

2002 ◽  
Vol 110 (2) ◽  
pp. 9-15 ◽  
Author(s):  
W Freedman
Keyword(s):  

1998 ◽  
Vol 14 (1) ◽  
pp. 62-70 ◽  
Author(s):  
Richard H. Dana

This paper describes the status of multicultural assessment training, research, and practice in the United States. Racism, politicization of issues, and demands for equity in assessment of psychopathology and personality description have created a climate of controversy. Some sources of bias provide an introduction to major assessment issues including service delivery, moderator variables, modifications of standard tests, development of culture-specific tests, personality theory and cultural/racial identity description, cultural formulations for psychiatric diagnosis, and use of findings, particularly in therapeutic assessment. An assessment-intervention model summarizes this paper and suggests dimensions that compel practitioners to ask questions meriting research attention and providing avenues for developments of culturally competent practice.


1962 ◽  
Vol 7 (4) ◽  
pp. 156-156
Author(s):  
C. SHAGASS

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