The present status of the parasegment

Development ◽  
1988 ◽  
Vol 104 (Supplement) ◽  
pp. 61-65 ◽  
Author(s):  
Peter A. Lawrence

The hypothesis that parasegments are a fundamental unit of design in the Drosophila embryo was put forward three years ago (Martinez-Arias & Lawrence, Nature 313, 639-642, 1935). Here, I summarize new evidence in favour of the hypothesis.

1978 ◽  
Vol 48 ◽  
pp. 175-178 ◽  
Author(s):  
K. J. Johnston
Keyword(s):  

A summary of results for radio astrometry with baselines ≤ 35 km and priorities for future work are given.


1978 ◽  
Vol 48 ◽  
pp. 31-35
Author(s):  
R. B. Hanson

Several outstanding problems affecting the existing parallaxes should be resolved to form a coherent system for the new General Catalogue proposed by van Altena, as well as to improve luminosity calibrations and other parallax applications. Lutz has reviewed several of these problems, such as: (A) systematic differences between observatories, (B) external error estimates, (C) the absolute zero point, and (D) systematic observational effects (in right ascension, declination, apparent magnitude, etc.). Here we explore the use of cluster and spectroscopic parallaxes, and the distributions of observed parallaxes, to bring new evidence to bear on these classic problems. Several preliminary results have been obtained.


Author(s):  
William Theurkauf

Cell division in eucaryotes depends on coordinated changes in nuclear and cytoskeletal components. In Drosophila melanogaster embryos, the first 13 nuclear divisions occur without cytokinesis. During the final four divisions, nuclei divide in a uniform monolayer at the surface of the embryo. These surface divisions are accompanied by dramatic changes in cortical actin and microtubule structure (Karr and Alberts, 1986), and inhibitor studies indicate that these changes are essential to orderly mitosis (Zalokar and Erk, 1976). Because the early embryo is syncytial, fluorescent probes introduced by microinjection are incorporated in structures associated with all of the nuclei in the blastoderm. In addition, the nuclei divide synchronously every 10 to 20 min. These characteristics make the syncytial blastoderm embryo an excellent system for the analysis of mitotic reorganization of both nuclear and cytoskeletal elements. However, the Drosophila embryo is a large cell, and resolution of cytoskeletal filaments and nuclear structure is hampered by out-of focus signal.


2007 ◽  
Vol 40 (9) ◽  
pp. 36
Author(s):  
BRUCE JANCIN
Keyword(s):  

2001 ◽  
Vol 58 (6) ◽  
pp. 362-366 ◽  
Author(s):  
Matius P. Stürchler ◽  
R. P. Steffen
Keyword(s):  

Impfungen sind einfache und effektive Maßnahmen zur Verhinderung von Reisekrankheiten. Compliance-Probleme sind gering, da alle Impfungen noch vor Abreise verabreicht werden und bei manchen Impfungen nur eine Dosis für den zuverlässigen Schutz nötig ist. Für jeden Reisenden sind die Hepatitis A- und die Diphtherie-Tetanus-Impfung empfohlen, für Asien und Afrika auch die Polioimpfung. Bei Reisen >30 Tagen, jüngeren Personen und Reisenden mit Risikoverhalten sollte immer auch eine Hepatitis B-Impfung, eventuell als Kombination mit Hepatitis A in Betracht gezogen werden. Je nach Reisestil, -destination und -dauer können auch weitere Impfungen wie z.B. die Typhus-, Tollwut-, Zeckenenzephalitis-, Grippe-, Masern-Mumps-Röteln-, Gelbfieber-, Meningokokkenmeningitis- und die Japanische Enzephalitis-Impfung in Frage kommen. Mehrere Impfungen können gleichzeitig verabreicht werden – eine Staffelung ist nicht nötig. i BAG Supplementum VI, Stand Juli 2000 «Impfungen für Auslandreisende»; http://www.admin.ch/bag/infekt/prev/reisemed/index.htm; Safetravel http://www.safetravel.ch; Tropimed


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