scholarly journals Gaia-2MASS 3D maps of Galactic interstellar dust within 3 kpc

2019 ◽  
Vol 625 ◽  
pp. A135 ◽  
Author(s):  
R. Lallement ◽  
C. Babusiaux ◽  
J. L. Vergely ◽  
D. Katz ◽  
F. Arenou ◽  
...  
Keyword(s):  
Interstellar Dust ◽  
Outer Part ◽  
Solar Neighborhood ◽  
Inversion Algorithm ◽  
Wide Range ◽  
Subsequent Step ◽  
History Of ◽  
The Individual ◽  
Perseus Arm ◽  
Do So

Gaia stellar measurements are currently revolutionizing our knowledge of the evolutionary history of the Milky Way. 3D maps of the interstellar dust provide complementary information and are a tool for a wide range of uses. We built 3D maps of the dust in the Local arm and surrounding regions. To do so, Gaia DR2 photometric data were combined with 2MASS measurements to derive extinction toward stars that possess accurate photometry and relative uncertainties on DR2 parallaxes smaller than 20%. We applied a new hierarchical inversion algorithm to the individual extinctions that is adapted to large datasets and to an inhomogeneous target distribution. Each step associates regularized Bayesian inversions in all radial directions and a subsequent inversion in 3D of all their results. Each inverted distribution serves as a prior for the subsequent step, and the spatial resolution is progressively increased. We present the resulting 3D distribution of the dust in a 6 × 6 × 0.8 kpc3 volume around the Sun. Its main features are found to be elongated along different directions that vary from below to above the mid-plane. The outer part of Carina-Sagittarius, mainly located above the mid-plane, the Local arm/Cygnus Rift around and above the mid-plane, and the fragmented Perseus arm are oriented close to the direction of circular motion. The spur of more than 2 kpc length (nicknamed the split) that extends between the Local Arm and Carina-Sagittarius, the compact near side of Carina-Sagittarius, and the Cygnus Rift below the Plane are oriented along l ~40 to 55°. Dust density images in vertical planes reveal a wavy pattern in some regions and show that the solar neighborhood within ~500 pc remains atypical by its extent above and below the Plane. We show several comparisons with the locations of molecular clouds, HII regions, O stars, and masers. The link between the dust concentration and these tracers is markedly different from one region to the other.

ExpanDrogram: Dynamic Visualization of Big Data Segmentation over Time

2021 ◽  
Vol 13 (2) ◽  
pp. 1-27
Author(s):  
A. Khalemsky ◽  
R. Gelbard
Keyword(s):  
Big Data ◽  
Visual Presentation ◽  
Trend Detection ◽  
Dynamic Visualization ◽  
Segmentation Process ◽  
Key Points ◽  
Wide Range ◽  
History Of ◽  
The Individual ◽  
Over Time

In dynamic and big data environments the visualization of a segmentation process over time often does not enable the user to simultaneously track entire pieces. The key points are sometimes incomparable, and the user is limited to a static visual presentation of a certain point. The proposed visualization concept, called ExpanDrogram, is designed to support dynamic classifiers that run in a big data environment subject to changes in data characteristics. It offers a wide range of features that seek to maximize the customization of a segmentation problem. The main goal of the ExpanDrogram visualization is to improve comprehensiveness by combining both the individual and segment levels, illustrating the dynamics of the segmentation process over time, providing “version control” that enables the user to observe the history of changes, and more. The method is illustrated using different datasets, with which we demonstrate multiple segmentation parameters, as well as multiple display layers, to highlight points such as new trend detection, outlier detection, tracking changes in original segments, and zoom in/out for more/less detail. The datasets vary in size from a small one to one of more than 12 million records.

Memoirs: Notes on the Maturation of the Ovum of Alcyonium digitatum

1905 ◽  
Vol s2-49 (195) ◽  
pp. 493-505
Author(s):  
M. D. HILL
Keyword(s):  
Egg Cell ◽  
Whole Process ◽  
Material Preparations ◽  
Polar Bodies ◽  
Female Pronucleus ◽  
History Of ◽  
The Many ◽  
The Individual ◽  
Nuclear History ◽  
Do So

Although the foregoing accouut is obviously incomplete, yet it is possible to draw some conclusions. I believe we have shown that: (a) The egg of Aleyonium produces no polar bodies in the ordinary sense of the word. (b) That the division of the female pronucleus before the entrance of the spermatozoon is irregular and amitotic. (c) That no chromatiu leaves the egg in the stage of ovocyte I, to use Boveri's nomenclature. (d) That the female pronucleus completely disappears. (s) That there are no bodies that can be termed chromosomes throughout the whole process. (f) That the first segmentation nucleus is formed in a way (unknown) that must in any case be unlike anything hitherto described. Furthermore I believe, though I cannot state so positively, that: (g) A process takes place that may roughly be compared to the formation of polar bodies, but they disintegrate and do not leave the cell. So far as I have ascertained nothing in the shape of extrusion takes place. It is, however, curious to note that the nearest account that I have been able to find of like behaviour in an egg nucleus is that of Sfcoeckel.1 This author found in a human ovary certain of the ova containing large nuclei, the membrane of which, as a rule, was well marked, but "oft geht diese scharfe Abgrenzung auch verloren. Die Konturen werden unregelmässeg Zackig, verschwommen."...Stoeckel believed that these changes in form were the beginning of amitotic nuclear divisions, giving rise to binucleated ova, of which he found several. I know of no other assumption of the direct division of an egg nucleus before fertilisation. (h) The first segmentation nucleus is derived from the male pronucleus, though it is quite possible that chromatin equal in amount to that of the male may also be derived from the female pronucleus, though all trace of the latter has been lost. If the foregoing statements be only partially true, it is obvious that a great gulf is fixed between the maturation processes in the egg of Alcyonium and all hitherto described cases. For this reason I am very loth to do more than state the bare conclusions to which I have come. To the best of my belief, no author has described amitotic nuclear divisions in the formation of polar bodies. We seem to have to deal with perfectly abnormal conditions. Nevertheless we are forced to admit that the maintenance of the individual parental chromosomes in a fertilised egg-cell is not universal. On the contrary, all trace of the chromatin of the original egg nucleus is lost. Furthermore, there are several instances among the protozoa of the breaking up and reorganisation of the nucleus. This occurs in many Ciliates. For instance : In ‘Oxytricha and Lacrymaria’ Gruber has shown that the meganucleus breaks up into minute fragments which become scattered through the protoplasm, but eventually reunite into a single body. So much attractive speculation has been based on the ordinarily observed facts of maturation and fertilisation that we feel almost bound to assume that these processes are the same iu all metazoa. But it is obvious that in certain cœlenterates we have facts before us that cannot be brought into line with what we feel we have a right to expect. At present the affair is a mystery. Pending farther investigation it were unwise to speculate on the possible meaning of these phenomena, however much one may be tempted to do so. In case that what I have observed, and still more failed to observe, may induce some other zoologist to follow this cytological byeway, I can only hope that he will find this paper a path over which it may not be necessary to retrace his steps. There would seem to be four points to which attention should be specially directed: (a) The nuclear history of the germ-cells from their earliest "Anlagen." (b) The mode of formation of the polar bodies. (c) The actual penetration of the spermatozoon. (d) The way in which the first segmentation nucleus is built up. Lastly, I have but to express my sincere thanks to Professor Hickson for his kindness in allowing me the use of his material, preparations, and notes, and for the many fruitful suggestions that I have received from him.

“Girlie Man, Manly Girl, It’s all the Same to me”

2019 ◽  
pp. 22-35
Keyword(s):  
Life History ◽  
Male Characters ◽  
Drag King ◽  
Historical Archive ◽  
Wide Range ◽  
Queer Culture ◽  
Current Events ◽  
History Of ◽  
Community Shifts ◽  
Do So

First published in 1983 in Womanews, and later widely syndicated, Alison Bechdel’s Dykes To Watch Out For (DTWOF) series not only created an unparalleled historical archive of queer culture, it also shaped both the lesbian comix and queer comics that came after it in remarkable ways. Through her use of a wide range of characters having pointed conversations about then-current events and politics, debating identity, desire, and shifting representation, or simply going out to dinner at Café Topaz, the local vegetarian restaurant, Bechdel catalogues a life history of these lesbians and their community—even as that community shifts in unanticipated ways, as our understanding of binary gender shifts and continues to do so today. For a strip that initially included no men, DWTOF ended up including a number of male characters in order to explore what “male” meant through drag king culture, non-binary characters, and characters who identify as transgender.

Origins

2020 ◽  
pp. 11-30
Author(s):  
Phillip Brown
Keyword(s):  
Human Capital ◽  
Adam Smith ◽  
Wealth Creation ◽  
Capital Theory ◽  
Ibn Khaldun ◽  
Wide Range ◽  
Human Labor ◽  
History Of ◽  
The Individual

This chapter discusses the history of human capital theory. Before the mid-twentieth century the idea of human capital had a checkered history. Ideas linking the role of human labor to wealth creation can be traced to the works of Aristotle, Ibn Khaldun, and Thomas Aquinas. The chapter examines the ideas posed by notable economic theorists and thinkers such as Adam Smith, Alfred Marshall, Theodore Schultz, and Gary Becker. It shows how the ideas developed by these thinkers extended to a wide range of issues concerning the relationship between education and the labor market. In turn, they were able to influence policy in such powerful ways that their legacy remains. Above all, their influence shaped the way education is viewed in many countries: as an investment in the economic fortunes of the individual and the nation. This view gradually emerged as the dominant one, but was triumphantly sealed by the advent of neoliberalism in the 1980s.

scholarly journals Investigating the interstellar dust through the Fe K-edge

2017 ◽  
Vol 609 ◽  
pp. A22 ◽  
Author(s):  
D. Rogantini ◽  
E. Costantini ◽  
S. T. Zeegers ◽  
C. P. de Vries ◽  
W. Bras ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Cross Sections ◽  
Interstellar Dust ◽  
Effective Area ◽  
European Synchrotron Radiation Facility ◽  
Galactic Centre ◽  
X Rays ◽  
X Ray ◽  
Wide Range ◽  
The Individual

Context. The chemical and physical properties of interstellar dust in the densest regions of the Galaxy are still not well understood. X-rays provide a powerful probe since they can penetrate gas and dust over a wide range of column densities (up to 1024 cm-2). The interaction (scattering and absorption) with the medium imprints spectral signatures that reflect the individual atoms which constitute the gas, molecule, or solid. Aims. In this work we investigate the ability of high resolution X-ray spectroscopy to probe the properties of cosmic grains containing iron. Although iron is heavily depleted into interstellar dust, the nature of the Fe-bearing grains is still largely uncertain. Methods. In our analysis we use iron K-edge synchrotron data of minerals likely present in the ISM dust taken at the European Synchrotron Radiation Facility. We explore the prospects of determining the chemical composition and the size of astrophysical dust in the Galactic centre and in molecular clouds with future X-ray missions. The energy resolution and the effective area of the present X-ray telescopes are not sufficient to detect and study the Fe K-edge, even for bright X-ray sources. Results. From the analysis of the extinction cross sections of our dust models implemented in the spectral fitting program SPEX, the Fe K-edge is promising for investigating both the chemistry and the size distribution of the interstellar dust. We find that the chemical composition regulates the X-ray absorption fine structures in the post edge region, whereas the scattering feature in the pre-edge is sensitive to the mean grain size. Finally, we note that the Fe K-edge is insensitive to other dust properties, such as the porosity and the geometry of the dust.

scholarly journals THE VISUAL SYSTEMS OF EURYHALINE FISHES

1941 ◽  
Vol 25 (2) ◽  
pp. 235-245 ◽  
Author(s):  
George Wald
Keyword(s):  
Visual System ◽  
Fresh Water ◽  
Brook Trout ◽  
White Perch ◽  
Terrestrial Vertebrates ◽  
Visual Systems ◽  
Formal Requirement ◽  
Wide Range ◽  
History Of ◽  
The Individual

1. The retinas of all marine fishes so far examined except the Labridae, and of all terrestrial vertebrates contain the rhodopsin system alone; those of fresh water fishes the porphyropsin system alone. In the present paper the visual systems of a number of euryhaline fishes are examined—fishes capable of existence in a wide range of salinities, though usually restricted in spawning either to the sea (catadromous) or to fresh water (anadromous). 2. The retinas of the anadromous salmonids (brook trout, rainbow trout, and chinook salmon) contain mixtures of the rhodopsin and porphyropsin systems, predominantly the latter. The retinas of the catadromous eel and the killifish also contain mixtures of both systems, but in reverse proportions. The retinas of the anadromous white perch and alewife contain the porphyropsin system alone. 3. There is therefore an extensive parallelism between the salinity relations of these animals and the composition of their visual systems. All of them possess predominantly or exclusively the visual system commonly associated with the environment in which the fish spawns. 4. These patterns are fixed genetically, and are to a first approximation independent of the history of the individual. They may represent transitional stages in the evolutionary migration of fishes to and from the sea. The presence of both types of visual system in the retinas of some euryhaline fishes incidentally satisfies one formal requirement of two-component color vision.

scholarly journals Artistic Genius versus the Hanse Canon from the Late Middle Ages to the Early Modern Age in Tallinn

2020 ◽  
Vol 20 ◽  
pp. 59-80
Author(s):  
Juhan Maiste
Keyword(s):  
Middle Ages ◽  
The Other ◽  
15Th Century ◽  
Late Middle Ages ◽  
Wide Range ◽  
Working Together ◽  
History Of ◽  
The Veil ◽  
The One ◽  
The Individual

In the article, the author examines one of the most outstanding andproblematic periods in the art history of Tallinn as a Hanseatic city,which originated, on the one hand, in the Hanseatic tradition andthe medieval approach to Gothic transcendental realism, and onthe other, in the approach typical of the new art cities of Flanders,i.e. to see a reflection of the new illusory reality in the pictures. Acloser examination is made of two works of art imported to Tallinnin the late 15th century, i.e. the high altar in the Church of the HolySpirit by Bernt Notke and the altarpiece of Holy Mary, whichwas originally commissioned by the Brotherhood of Blackheadsfor the Dominican Monastery and is now in St Nicholas’ Church.Despite the differences in the iconography and style of the twoworks, their links to tradition and artistic geography, which in thisarticle are conditionally defined as the Hanse canon, are apparentin both of them.The methods and rules for classifying the transition from theMiddle Ages to the Modern Era were not critical nor exclusive.Rather they included a wide range of phenomena on the outskirtsof the major art centres starting from the clients and ending with the semantic significance of the picture, and the attributes that wereemployed to the individual experiences of the different masters,who were working together in the large workshops of Lübeck, andsomewhat later, in Bruges and Brussels.When ‘reading’ the Blackheads’ altar, a question arises of threedifferent styles, all of them were united by tradition and the waythat altars were produced in the large workshops for the extensiveart market that stretched from one end of the continent to the other,and even further from Lima to Narva. Under the supervision ofthe leading master and entrepreneur (Hans Memling?) two othermasters were working side by side in Bruges – Michel Sittow, whowas born in Tallinn, and the Master of the Legend of Saint Lucywere responsible for executing the task.In this article, the author has highlighted new points of reference,which on the one hand explain the complex issues of attributionof the Tallinn Blackheads’ altar, and on the other hand, placethe greatest opus in the Baltics in a broader context, where, inaddition to aesthetic ambitions, both the client and the workshopthat completed the order, played an extensive role. In this way,identifying a specific artist from among the others would usuallyremain a matter of discussion. Tallinn was a port and a wealthycommercial city at the foregates of the East where it took decadesfor the spirit of the Renaissance to penetrate and be assimilated.Instead of an unobstructed view we are offered uncertain andoften mixed values based on what we perceive through the veil ofsemantic research.

scholarly journals University Settlements in Great Britain

1911 ◽  
Vol 4 (2) ◽  
pp. 175-203 ◽  
Author(s):  
Percy Ashley
Keyword(s):  
Great Britain ◽  
British Empire ◽  
Social Life ◽  
The Past ◽  
Main Emphasis ◽  
Wide Range ◽  
Settlement Movement ◽  
History Of ◽  
The Individual ◽  
The University

A quarter of a century has now elapsed since the foundation of Toynbee Hall in the east of London inaugurated the “University Settlement” movement in the vast and then almost inchoate capital of the British Empire; and the present time seems therefore appropriate for an attempt to form some estimate of the past results and future possibilities of the movement, which soon spread to other towns of England and Scotland. Yet such an undertaking is beset with serious difficulties. Throughout the whole history of the settlements there is indeed apparent an essential identity of purpose, an underlying uniformity of motive; but the individual institutions have been the outcome of the action of various bodies of persons whose aims, as formally expressed, seem often very diverse; different groups have laid the main emphasis on different objects and methods, and what has been counted as triumphant success by one group has been deemed of relatively small importance by another. Further, the wide range of the activities of the settlements, the multifarious nature of their interests and work, render it practically impossible for any one observer to comprehend the whole in his single survey; and the selection which he must needs make tends almost inevitably to be determined, and it may be even unfairly biassed, by his own personal predilections. Within this narrower range, moreover, there is no certain standard by which to measure success or failure; the value of the work accomplished by a settlement is not to be judged solely, or even chiefly, by the statistics of its classes and clubs. If it has realized its objects, however imperfectly, it has exercised upon the surrounding community, in conjunction with all other institutions that in any way and by any means make for good, a subtle and permeating influence which has resulted in a progressive amelioration of social life; but, for the very reason that this achievement is the result of a number of co-operating forces, the share of the settlement therein cannot be isolated or defined with any exactitude.

Assessment of Suicide Risk in Psychiatric In-Patients

1984 ◽  
Vol 145 (5) ◽  
pp. 467-469 ◽  
Author(s):  
H. G. Morgan ◽  
Pamela Priest
Keyword(s):  
Suicide Risk ◽  
Traditional Approach ◽  
Significant Loss ◽  
Considerable Proportion ◽  
Complex Issue ◽  
Wide Range ◽  
History Of ◽  
Social Turmoil ◽  
Commit Suicide ◽  
Do So

Assessment of suicide risk is an important and complex issue. We know that a considerable proportion of those who kill themselves seek help before they do so (Robins et al, 1959; Barraclough et al, 1974), and it is therefore essential both to recognise indices of suicide risk and to react appropriately to them. This means being sensitive to many personal, social and environmental factors, rendered more problematic by the fact that each individual is uniquely responsive to life events. The traditional approach, based on clinical epidemiological considerations, has long identified such factors as depression, alcoholism, increasing age, social isolation, physical illness and significant loss as important correlates of suicide, but there is now increasing evidence of other important factors which are frequently associated with suicide. Patients who commit suicide exhibit a wide range of behavioural problems which may hamper recognition of underlying suicide risk (Seager & Flood, 1965); and young adults with a history of chronic social turmoil are highly represented amongst suicides (Ovenstone & Kreitman 1974).

Comprehensive Casing Corrosion Inspection Using Multi-Frequency Array EM Technology

2021 ◽  
Author(s):  
Mohamed Larbi Zeghlache ◽  
Abdulaziz Bazaid ◽  
Freeman Hill ◽  
Nacer Guergueb
Keyword(s):  
Frequency Domain ◽  
Continuous Wave ◽  
Synthetic Data ◽  
Thickness Measurement ◽  
Wave Mode ◽  
Assessment Process ◽  
Metal Loss ◽  
Inversion Algorithm ◽  
Wide Range ◽  
The Individual

Abstract Historically, only total metal thickness measurement was possible using frequency domain electromagnetic (EM) logging tools. With advances in technology, it is critical to develop a frequency domain alternative answer using a multi-frequency array EM pipe inspection tool to accurately estimate the individual wall thicknesses of as many as five concentric pipes. Results from yard testing in a special design mockup, as well as field logs, are demonstrated as part of the technology assessment process. The new multi-frequency array EM tool uses the eddy current principle and includes two transmitters and eight receivers. It operates in continuous wave mode at multiple frequencies. Optimized transmitter-receiver spacing configurations and multi-frequency operation provide sufficiently diverse information to help assess the metal loss in each individual pipe for a wide range of configurations. The tool uses a sophisticated workflow of data processing and inversion algorithms to decouple individual thickness information from the measured data. The capabilities of the tool are demonstrated using two 400-ft long pipe mockups, each having 18 different combinations of overlapping and non-overlapping defects in five-, four-, and three-pipe sections. The configurations of the pipes used in the mockups were chosen to cover typical well completions commonly used in the Middle East. Data from the mockups are validated using synthetic data generated using two-dimensional (2D) computer models. The tool has delivered unprecedented accurate assessments of the fourth and fifth pipes, as well as an accurate assessment of the commonly evaluated first, second, and third pipes. The sensitivity of the inversion to model mismatches, such as those introduced by decentralized pipes, is studied by deliberately decentralizing one of the mockup pipes over a length of the log. An algorithm designed to correct for pipe eccentricity is also demonstrated. The results from the surface testing are discussed along with the performance of the tool in a test well with pipe configurations similar to the mockups. In the studied test well, the tool was able to identify defects in the outermost strings. This solution utilizes a novel inversion algorithm of big data from multi-frequency array sensors to derive individual pipes corrosion. This technology can significantly improve proactive decision making for mature well operations, especially in areas with high corrosion rates and shallow outer casing corrosion.

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