A refined test for X-ray induced dominant lethals inDrosophila

Zusammenfassung Die nach Röntgenbestrahlung frisch abgelegter besamterDrosophila-Eier registrierbare Letalität kann nach verschiedenen Letalsyndromen aufgegliedert werden. Zur Auswertung stehen Computerprogramme zur Verfügung. Spezielle Tests zeigten, dass mit der beschriebenen Zuchtanordnung bestrahlte und unbestrahlte Populationen, von denen 25–30 Puppen (bzw. Fliegen) pro Zuchtglas überleben, ohne Beeinflussung durch ungünstige Zuchtbedingungen auf dominante Letalfaktoren geprüft werden können.

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Work supported by Schweizerischer Nationalfonds zur Förderung der wissenschaftlichen Forschung and Jubiläumsfonds 1930 der ETH.     

Induced dominant lethals in female mice: Effects of triaziquone and phenylbutazone

Zusammenfassung Bei weiblichen Mäusen induzierte Triaziquon unter konventionellen Laboratoriumsbedingungen dominante Letalfaktoren, wenn die Substanz im Pro-Oestrus oder im Oestrus verabreicht wurde. Weniger gut geeignet erwies sich diese Applikation wenige Stunden nach Kopulation, da embryotoxische Wirkungen auftraten. Im Gegensatz zu Triaziquon führte Phenylbutazon — weiblichen Mäusen im Oestrus verabreichtnicht zu dominanten Letaleffekten.     

Differences in chromosome A arrangement between Drosophila madeirensis and Drosophila subobscura

The proximal half of the A (= X) chromosome of D. madeirensis has a gene arrangement very similar to the A1 or A6 inversions found in D. subobscura. Polytene chromosome analysis of hybrids between D. madeirensis and strains of D. subobscura homozygous for such inversions shows, however, that D. madeirensis has a gene arrangement different from any known for D. subobscura. These results provide evidence for a greater differentiation of the X chromosome in these species than has previously been described; it seems that the X chromosome is the only one that has undergone structural variation during the speciation process.     

A quantitative slide test for ATP

Résumé Un essai sur lamelle porte-objet a été mis au point pour la détermination quantitative du triphosphate d'adénosine. Il s'agit d'une modification de la réaction bien connue entre la luciférine et la luciférase dérivées de la luciole. Cet essai permet de déceler des quantités minuscules de l'ATP pouvant atteindre 10^–13 g.     

Effect of hyperthermia upon gamma-ray induced crossing-over in an excision repair deficient male Drosophila melanogaster

Hyperthermia of 1 h at 38 degrees C did increase gamma-ray induced crossing-over in meiotic cells of male larvae and adults. However, there was considerably less effect of the heat treatment upon radiation induced crossing-over (a chromosome breakage event) in an excision repair mutant y mei-9a.     

A simple stirring device for test tube work

Zusammenfassung Ein einfach herzustellendes, luftgetriebenes Umrührgerät für kleinere Flüssigkeitsmengen in Probierröhren wird beschrieben.     

Microtubule inhibitors block the morphological changes induced in Drosophila blood cells by a parasitoid wasp factor

The shape change of Drosophila melanogaster blood cells (lamellocytes) from discoidal to bipolar that is caused by a factor from the female parasitoid Leptopilina heterotoma is blocked by the tubulin inhibitors vinblastine and vincristine in vitro. The actin inhibitor, cytochalasin B, causes arborization of Drosophila lamellocytes and acts synergistically with the wasp factor to alter lamellocyte morphology. Lamellocyte aborization induced by cytochalasin B is blocked by simultaneous treatment with vinblastine. These observations indicate that the changes in lamellocyte shape induced by both the wasp factor and cytochalasin B require microtubule assembly.     

A closed expression for certain probabilities in Wilcoxon's two sample test

Zusammenfassung Gewisse Wahrscheinlichkeiten, welche in der Anwendung von Wilcoxons Test für das Problem der zwei Stichproben wichtig sind, werden mittels einer Determinante geschlossen ausgewertet. Diese Determinante wurde bereits vonBrioschi auf ein Problem in der Theorie der Partitionen von ganzen Zahlen angewandt.     

A Bayesian threshold nonlinearity test for financial time series

We propose in this paper a threshold nonlinearity test for financial time series. Our approach adopts reversible‐jump Markov chain Monte Carlo methods to calculate the posterior probabilities of two competitive models, namely GARCH and threshold GARCH models. Posterior evidence favouring the threshold GARCH model indicates threshold nonlinearity or volatility asymmetry. Simulation experiments demonstrate that our method works very well in distinguishing GARCH and threshold GARCH models. Sensitivity analysis shows that our method is robust to misspecification in error distribution. In the application to 10 market indexes, clear evidence of threshold nonlinearity is discovered and thus supporting volatility asymmetry. Copyright © 2005 John Wiley & Sons, Ltd.     

A microscopic test for rapid detection of antibodies againstMycoplasma pneumoniae

Zusammenfassung Die Filamentform der an Glas wachsenden Zellen vonM. pneumoniae wird durch homologes Antiserum in Gegenwart von aktivem Pferdeserum zerstört. Diese Reaktion ist spezifisch und kann auch zum Nachweis von Antikörpern in menschlichen Seren verwendet werden. Ein Zusammenhang der an der Reaktion beteiligten Antikörper mit den im Stoffwechselhemmtest nachzuweisenden Antikörpern wird diskutiert.     

A triple test for screening biological activity of prostacyclin analogues

Summary 6,9-Thiaprostacyclin was used as a representative of prostacyclin analogues with the aim to design the most convenient procedure for evaluation of vasodilator, anti-platelet and other biological properties within this new group of potential anti-thrombotic agents.     

A robust Cusum test for SETAR‐type nonlinearity in time series

As a part of an effective self‐exciting threshold autoregressive (SETAR) modeling methodology, it is important to identify processes exhibiting SETAR‐type nonlinearity. A number of tests of nonlinearity have been developed in the literature. However, it has recently been shown that all these tests perform poorly for SETAR‐type nonlinearity detection in the presence of additive outliers. In this paper, we develop an improved test for SETAR‐type nonlinearity in time series. The test is an outlier‐robust test based on the cumulative sums of ordered weighted residuals from generalized maximum likelihood fits. A Monte Carlo study confirms that the proposed test is competitive with existing tests for data from uncontaminated SETAR models and superior to them for SETAR data contaminated with additive outliers. Copyright © 2008 John Wiley & Sons, Ltd.