748 research outputs found

    SOME NOTES ABOUT THE NATURE RESERVE PULAU PANAITAN (PRINSENEILAND) IN STRAIT SUNDA, with special reference to the avifauna

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    Fro!ll August the 30th till October the 5th 1951, Kebun Raya Indonesia(Botanical Gardens) at Bogor organized an expedition to the islandmentioned above.Up till then the island was nearly "terra incognita" from a scientific point of view, for no botanical or zoological investigation had ever beenmade, though some scientists (a.o. MOLLIER, DAMMERMAN, ENDERT) paid short visits to the area

    A Hipparcos census of the nearby OB associations

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    A comprehensive census of the stellar content of the nearby OB associations is presented, based on Hipparcos positions, proper motions, and parallaxes. Moving groups are identified by combining de Bruijne's refurbished convergent point method with the `Spaghetti method' of Hoogerwerf & Aguilar. Monte Carlo simulations are used to estimate the expected number of interloper field stars. Astrometric members are listed for 12 young stellar groups, out to a distance of ~650 pc. These are the 3 subgroups Upper Scorpius, Upper Centaurus Lupus and Lower Centaurus Crux of Sco OB2, as well as Vel OB2, Tr 10, Col 121, Per OB2, alpha Persei (Per OB3), Cas-Tau, Lac OB1, Cep OB2, and a new group designated as Cep OB6. The selection procedure corrects the list of previously known astrometric and photometric B- and A-type members, and identifies many new members, including a significant number of F stars, as well as evolved stars, e.g., the Wolf-Rayet stars gamma^2 Vel (Vel OB2) and EZ CMa (Col 121), and the classical Cepheid delta Cep in Cep OB6. In the nearest associations the later-type members include T Tauri objects and other pre-main sequence stars. Astrometric evidence for moving groups in the fields of R CrA, CMa OB1, Mon OB1, Ori OB1, Cam OB1, Cep OB3, Cep OB4, Cyg OB4, Cyg OB7, and Sct OB2, is inconclusive, due to their large distance or unfavorable kinematics. The mean distances of the well-established groups are systematically smaller than previous estimates. The mean motions display a systematic pattern, which is discussed in relation to the Gould Belt. Six of the 12 detected moving groups do not appear in the classical list of nearby OB associations. The number of unbound young stellar groups in the Solar neighbourhood may be significantly larger than thought previously.Comment: 51 pages, 30 PostScript figures, 6 tables in PostScript format, default LaTeX using psfig.sty; accepted for publication in the Astronomical Journal, scheduled for January 1999 issue. Abbreviated abstrac

    OB Associations

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    Since the previous (1990) edition of this meeting enormous progress in the field of OB associations has been made. Data from X-ray satellites have greatly advanced the study of the low-mass stellar content of associations, while astrometric data from the Hipparcos satellite allow for a characterization of the higher-mass content of associations with unprecedented accuracy. We review recent work on the OB associations located within 1.5 kpc from the Sun, discuss the Hipparcos results at length, and point out directions for future research.Comment: To appear in The Physics of Star Formation and Early Stellar Evolution II, eds C.J. Lada & N. Kylafis (Kluwer Academic), 30 pages, 9 EPS-figures, LaTeX using crckapb.sty, epsfig.sty, amssymb.st

    De staf van het Amerikaanse congres

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    In the introductory part of the article, a summary is given of some American : research data on the functioning of the U.S. Gongress. The most frequent role-orientation of the members of the House of Representatives is that of the ‘tribune’. The members most satisfied with the way in which Congress functions I are however those with the role-orientation of the ‘broker’. The problem mentioned most frequently by the respresentatives is lack of information. The main goals which the members of both houses try to reach by means of the expansion of the staff are: (1) strengthening or maintaining the influence of Congress on legislation and oversight of the administration; (2) better communication with the citizens; (3) more expert and more independent information for the members of Congress. i i The average senator now ha.s a personal staff of 13 to 16 persons. A represenI tative normally has a staff of 6 or 7 members. The comittee staffs consist of I 640 persons in the House and 482 in the Senate. In addition there is also the Legislative Reference Service (LRS) of the Library of Congress (220 persons). The activities of the staff are extremely varied. Generally speaking, the 1 committee staff concentrates on legislation and oversight of the administration. The personal staff of the members deals mainly with the communication between the member and his constituents. The LRS concentrates on informing j committees, members and constituents. Many members are not satisfied with the way in which Congress functions. I Most of them think that a further growth of the staff — both in quality and quantity — is needed. It has been said that Congress, facing the growth of . the governmental bureaucracy, should bureaucratize itself. I The problems facing the parliament of the Netherlands, though not by far ' as gigantic, are more or less of the same nature as those related to the manner of functioning of the U.S. Congress. The staff of the Dutch Parliament is still extremely small. A new development is that since 1966 the parliamentary parties are allowed some money for their own staff
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