246,142 research outputs found
Current Status of Radio Source Databases
We review the history and present status of radio-source catalogue archiving
and on-line retrieval of radio source data. Large efforts were spent by the
first author in collecting and restoring electronic versions of new and old
source catalogues. Some 67 catalogues with ~520,000 entries were searchable via
the "Einstein On-line Service" (EOLS). When EOLS lost maintenance support in
1994 a group at SAO (Russia) started building software tools to search and
cross-identify objects between the major radio catalogues, maintained as the
"CATalog supporting System" (CATS) at the Special Astrophysical Observatory
(SAO, Russia). The independent efforts in east and west have recently been
joined. Almost 400 different source lists with ~2,000,000 entries have been
archived (and partly prepared) by us. All 5C and Penticton "P"-surveys and many
of the published WSRT survey lists are now available. CATS has been developed
by O. Verkhodanov, S. Trushkin, V. Chernenkov at SAO primarily to support
RATAN-600 radio observations. CATS runs under LINUX and can process requests on
the basis of various net protocols and via email. Almost 70 well-known radio
source catalogues and tables with about 1.3 Mrecords are now available via ftp
from CATS, as well as their documentation files. Twenty of the larger tables
may be searched simultaneously for objects in rectangular boxes of coordinates.
New routines for cross-matching are in progress. More and more catalogues are
being folded into CATS. CATS is supported by RFBR grant 96-07-89075.Comment: 2 pages, no figures; to appear in Proc. "Observational Cosmology with
the New Radio Surveys", eds. M. Bremer, N. Jackson & I. Perez-Fournon, Kluwer
Acad. Pres
A Reverse Monte Carlo study of H+D Lyman alpha absorption from QSO spectra
A new method based on a Reverse Monte Carlo [RMC] technique and aimed at the
inverse problem in the analysis of interstellar (intergalactic) absorption
lines is presented. The line formation process in chaotic media with a finite
correlation length of the stochastic velocity field (mesoturbulence)
is considered. This generalizes the standard assumption of completely
uncorrelated bulk motions in the microturbulent approximation
which is used for the data analysis up-to-now. It is shown that the RMC method
allows to estimate from an observed spectrum the proper physical parameters of
the absorbing gas and simultaneously an appropriate structure of the velocity
field parallel to the line-of-sight. The application to the analysis of the H+D
Ly profile is demonstrated using Burles & Tytler [B&T] data for QSO
1009+2956 where the DI Ly line is seen at . The results
obtained favor a low D/H ratio in this absorption system, although our upper
limit for the hydrogen isotopic ratio of about is slightly
higher than that of B&T (D/H = ). We also
show that the D/H and N(HI) values are, in general, correlated, i.e. the
derived D-abundance may be badly dependent on the assumed hydrogen column
density. The corresponding confidence regions for an arbitrary and a fixed
stochastic velocity field distribution are calculated.Comment: 6 pages, LaTeX, 2 Postscript figures, to appear in "The Primordial
Nuclei and Their Galactic Evolution", eds. N. Prantzos, M. Tosi, R. von
Steiger (Kluwer: Dordrecht
EKSPLORASI DAN TRANSFIGURASI IKON, INDEKS, DAN SIMBOL TEKS PASAMBAHAN MINANGKABAU
Abstract: This study is concerned with the analysis of pasambahan in Minangkabau. The purpose of this study is to exploit icon, index, and symbol related to in terms of culture, escatology, ideology, identity, and philosophy. This analysis refers to qualitative by applying the Semiotic theory of teori Charles Sander peirce (1986) and Aart van Zoest (1993). A number of informants were also interviewed in order to sharpen the data analysis. The result showed that based on the exploration and transfiguration of pasambahan text in Minangkabau, reflected several changes of Minangkabau society nowadays
Metabolic Heat in Microbial Conflict and Cooperation
Many microbes live in habitats below their optimum temperature. Retention of
metabolic heat by aggregation or insulation would boost growth. Generation of
excess metabolic heat may also provide benefit. A cell that makes excess
metabolic heat pays the cost of production, whereas the benefit may be shared
by neighbors within a zone of local heat capture. Metabolic heat as a shareable
public good raises interesting questions about conflict and cooperation of heat
production and capture. Metabolic heat may also be deployed as a weapon.
Species with greater thermotolerance gain by raising local temperature to
outcompete less thermotolerant taxa. Metabolic heat may provide defense against
bacteriophage attack, by analogy with fever in vertebrates. This article
outlines the theory of metabolic heat in microbial conflict and cooperation,
presenting several predictions for future study
The effects of dominance on leadership and energetic gain: a dynamic game between pairs of social foragers
Although social behaviour can bring many benefits to an individual, there are also costs that may be incurred whenever the members of a social group interact. The formation of dominance hierarchies could offer a means of reducing some of the costs of social interaction, but individuals within the hierarchy may end up paying differing costs dependent upon their position within the hierarchy. These differing interaction costs may therefore influence the behaviour of the group, as subordinate individuals may experience very different benefits and costs to dominants when the group is conducting a given behaviour. Here, a state-dependent dynamic game is described which considers a pair of social foragers where there is a set dominance relationship within the pair. The model considers the case where the subordinate member of the pair pays an interference cost when it and the dominant individual conduct specific pairs of behaviours together. The model demonstrates that if the subordinate individual pays these energetic costs when it interacts with the dominant individual, this has effects upon the behaviour of both subordinate and the dominant individuals. Including interaction costs increases the amount of foraging behaviour both individuals conduct, with the behaviour of the pair being driven by the subordinate individual. The subordinate will tend to be the lighter individual for longer periods of time when interaction costs are imposed. This supports earlier suggestions that lighter individuals should act as the decision-maker within the pair, giving leadership-like behaviours that are based upon energetic state. Pre-existing properties of individuals such as their dominance will be less important for determining which individual makes the decisions for the pair. This suggests that, even with strict behavioural hierarchies, identifying which individual is the dominant one is not sufficient for identifying which one is the leader
Individual and collective identification in contemporary forensics
It has long been understood that individual and collective identification are inexorably intertwined. This convergence is not limited to genetics. This paper discusses the convergence of individual and collective identification in a comparative analysis of three other forensic areas: fingerprint analysis, microscopic hair comparison, and microbiome forensics. In all three case studies, we see purportedly individualizing technologies reverting, in a sense, to collective identification. Presumably, this has much to do with the perceived utility of collective identification. When knowing precisely who is the donor of a trace is not possible, or not useful, then knowing that the donor is ‘white,’ or ‘black,’ or ‘Middle Eastern’ begins to seem somehow useful. In each case, we also see that these collective identifications are ultimately founded on crude and broad, seemingly ‘commonsensical’ or ‘social,’ racial categories. These categories, meanwhile, are based on a less-than-fully-transparent combination of self-identification or official ascription. These suspect data are then transformed into seemingly persuasive scientific claims about the genetic attributes of this or that ‘race,’ ‘ethnicity,’ or ‘ancestry.’ Through this comparison the paper will explore how the individual and the collective are ‘done’ differently and similarly in different forensic disciplines
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Ion channels: structural basis for function and disease.
Ion channels are ubiquitous proteins that mediate nervous and muscular function, rapid transmembrane signaling events, and ionic and fluid balance. The cloning of genes encoding ion channels has led to major strides in understanding the mechanistic basis for their function. These advances have shed light on the role of ion channels in normal physiology, clarified the molecular basis for an expanding number of diseases, and offered new direction to the development of rational therapeutic interventions
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Black Italianità: Citizenship and Belonging in the Black Mediterranean
This article discusses the fraught relationship between legal citizenship and Black belonging as depicted in the works of two Black Italian women writers. The protagonists in the short story “Salsicce” (“Sausages”) by Igiaba Scego and the novella Kkeywa: Storia di una bimba meticcia by Carla Macoggi resist multiple forms of dispossession and struggle to hold on to the autonomy of their self-identification and cultural attachments. Both Scego and Macoggi affirm the necessity to reclaim the power of self-definition, self-representation, and political agency when reckoning with the citizenship project and its inherent exclusions. Thus, these writings showcase the importance of studying the dynamic body of Black literature in Italian and offer us insight into some of the racialized, gendered, and religious negotiations of Italian sociopolitics for Black people navigating life throughout Italy and the Mediterranean.
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