Showing papers by "University of Würzburg published in 1973"

Untersuchungen zur Festkörperzerstäubung bei schiefwinkligem Ionenbeschuß polykristalliner Metalloberflächen im Energiebereich um 1 keV

Abstract: The sputtering yieldS of polycrystalline targets of Al, Ti, Ni, Cu, Zr, Pd, Ag, Ta, W and Au bombarded with Ar+-ions of 1.05 keV has been measured as a function of the angle of incidence α of the bombarding particles. For polycrystalline Cu the influence of α onS has been determined for all kinds of noble gas ions, and with Xe+ as a function of the bombarding energy in the range of 0.5 to 2 keV. It is shown that present sputtering theories do not explain the behaviour of the measured normalized yield curvesS(α)/S(0), being different for the various ion-target-combinations and bombarding energies. Considering the contribution of particle ejection by a small number of collisions immediately beneath the bombarded surface a semi-empirical relation is found for the increment ΔS(α)=S(α)-S(0) between the sputtering yields at an oblique angle α and at normal incidence. ΔS(α) is given by the quantities involved in the first energy transfer between a primary and a target atom, by characteristic target properties and by a function of the bombarding angle α normalized to the individual angle for maximumS. The relation for ΔS(α) leads to an uniform description of the experimental results within the limits of error and is confirmed by other measurements on the influence of α.

Stomatal responses to changes in temperature at increasing water stress.

Abstract: The response of stomata to a gradual increase in temperature at increasing plant water stress was studied in a hot desert habitat (Negev, Israel) in the field, but under controlled temperature and humidity conditions. Four native species (Zygophyllum dumosum, Artemisia herba-alba, Hammada scoparia, Reaumuria negevensis) and one cultivated plant (Prunus armeniaca) were used in these studies. The stomatal response to temperature was compared with the response in well-irrigated plants of the same species.At low water stress, the diffusion resistance for water vapour decreased in response to a gradual increase in temperature. Transpiration increased accordingly. This response was reversible. All species responded in the same way. The opening of stomata with increasing temperature was apparently independent of the stomatal response regulated by atmospheric humidity. At high plant water stress, the stomatal response was reversed, i.e., the stomata closed when temperature was gradually increased. This stomatal closure was also independent of the closure regulated by atmospheric humidity. The plant water potential at which the stomatal response to temperature was reversed, differed among the species investigated.

Autoradiographic investigations of glial proliferation in the brain of adult mice. I. The DNA synthesis phase of neuroglia and endothelial cells.

Abstract: The proliferation of glial cells outside the subependymal layer of the lateral ventricle as well as of endothelial cells was studied autoradiographically in the brain of the adult and untreated mouse. The double labeling method with 3H- and 14C-thymidine was applied in order to show experimentally the existence of a DNA synthesis phase (S phase) and to measure its duration. Adult mice received a first injection of 14C-thymidine, two or four hours later a second injection of 3H-thymidine and were sacrificed one hour after the last injection by perfusion fixation. Double layer autoradiographs were made from serial sections of the region from the corpus callosum/commissura anterior up to the corpus callosum/commissura fornicis ventralis in order to register purely 3H-, doubly 3H- and 14C-, and purely 14C-labeled nuclei. From the ratio of all 3H-labeled cells with and without 14C to the purely 3H-labeled cells a DNA synthesis phase of 9.4 ± 0.5 hours for glial cells and one of 11.0 ± 2.2 hours for endothelial cells was obtained. Based on the first appearance of labeled mitoses and labeled pairs of glial cells after injections of labeled thymidine the G2 phase was estimated to be < three hours and G2 + M about five hours. The duration of the measured S phase as well as the appearance of labeled mitoses about three hours after application of labeled thymidine are very similar to these cycle parameters in many other somatic cells in different kinds of animals. This has led to the conclusion that a well-defined DNA synthesis phase with doubling of the DNA content and a successive mitosis also exists in glial and endothelial cells of the adult mouse brain.

Superfusion of the hypothalamus with gamma-aminobutyric acid. Effect on release of noradrenaline and blood pressure.

Abstract: The third ventricle and the aqueduct of anaesthetized cats were cannulated and the posterior area of the hypothalamus was stimulated with a monopolar electrode. Electrical stimulation of the posterior area evoked a rise of the arterial blood pressure which was inhibited by the injection of 0.2 ml of gammaaminobutyric acid (GABA, 2M) into the third ventricle. The impairment of the pressor response to electrical stimulation was accompanied by a fall of the “resting” blood pressure and depression of the respiration, presumably by action of GABA on brain areas in the vicinity of the fourth ventricle. In another series of experiments the posterior area was labelled with (±)-3H-noradrenaline and 2 h later superfused with a push-pull cannula and stimulated with the tip of the cannula. Superfusion with GABA (0.1 or 1 M) evoked a dose-dependent increase of release of catecholamines and enhanced the pressor response to electrical stimulation. 1×10−3 M of GABA enhanced the pressor response without increasing the spontaneous release of catecholamines but potentiated the output of radioactivity during electrical stimulation. Superfusion with sucrose (1 M) did not influence either pressor response or release of radioactive compounds. Superfusion with GABA increased slightly but significantly the relative concentration of catechols in the effluents and reduced that of normetanephrine. Pretreatment of animals with pargyline and tropolone evoked a pronounced increase of the relative concentrations of catechols in the effluent, while those of 3-methoxy-4-hydroxyphenylglycol and 3-methoxy-4-hydroxymandelic acid were strongly reduced. It is concluded that superfusion with high concentrations of GABA enhances the pressor response by increasing the release of catecholamines, while the effect of low GABA concentrations is due to facilitation of release of catecholamines from the adrenergic nerve endings during electrical stimulation.

Stabile Methylnickelverbindungen, II. Methyl(trimethylphosphin)nickel‐hydroxid und verwandte Verbindungen

Abstract: Es werden Darstellung und Eigenschaften zweikerniger Methylnickelverbindungen [LNi(CH3)X]2 (L = (CH3)3P, X = OH, OCH3, OC2H5, OSi(CH3)3, OC6H5, OC6H4CH3-(p), O2CH, O2CCH3, Cl) beschrieben. Aus den 1H-NMR-Spektren bei tiefen Temperaturen kann die Lage der Gleichgewichte zwischen cis- und trans-Formen bestimmt werden. Gemischt verbruckte Komplexe [LNi(CH3)X]. [LNi(CH3)Y] (L = (CH3)3P, X = OCH3, Y = OH, OC2H5, OC6H5) werden nur in der cis-Konfiguration beobachtet. Mit Trimethylphosphin werden aus den zweikernigen Titelverbindungen die monomeren Komplexe L2Ni(CH3)X (L = (CH3)3P, X = OC6H5, OC6H4CH3-(p), O2CCH3, Cl) gebildet.

1H‐, 13C‐ und 31P‐NMR‐Daten des Trimethylmethylenphosphorans

Abstract: In den 1H-, 13C- und 31P-NMR-Spektren von (CH3)3PCH2 wurden unter Anwendung von Doppelresonanz-Methoden die Kopplungskonstanten 1J(1H-13C), 1J(13C-31P), 2J(1H-C-31P) und ihre Vorzeichen bestimmt. Diese Daten und die chemischen Verschiebungen weisen auf eine dipolare Ylid-Struktur mit sp2-konfigurierten Carbanion-C-Atomen und sp3-konfigurierten Onium-P-Atomen hin. 1H, 13C, and 31P N.M.R. Data of Trimethylmethylenphosphorane In the 1H, 13C, and 31P n.m.r. spectra of (CH3)3PCH2 the coupling constants 1J(1H13C), 1J(13C-31P), 2J(1H-C-31P) and their relative signs have been measured with the help of double resonance experiments. These data and the chemical shifts indicate a dipolar ylid structure containing an sp2 carbanion and an sp3 onium center.

Conduction Band Parameters of Bi2See from Shubnikov‐de Haas Investigations

Abstract: The oscillatory magnetoresistance (Shubnikov-de Haas effect) was observed on n-type Bi2See single crystals between 1.6 and 4.2 K. The electron concentrations ranged from about 4 × 1017 to 4 × 1019 cm−3. Stationary magnetic fields up to 10.5 T were available. The angular dependence of the Shubnikov-de Haas periods revealed an almost rotational symmetry of the Fermi surface around the kc = 0 a parabolic e(k⊥) relation is found, parallel to the kc-axis an increasing nonparabolicity is evaluated. Only above 1019 electrons/cm3 the deviation of the shape of the Fermi surface from that of an ellipsoid of rotational symmetry becomes significant. The cyclotron mass mc perpendicular to the kc-axis (B ‖c) is determined to be 0.124 m0 in the whole concentration range. Fermi energies are evaluated up to 160 meV. The single-valley model for the lowest conduction band of Bi2See is confirmed. Der oszillatorische Anteil der magnetischen Widerstandsanderung (Shubnikov-de Haas-Effekt) wurde an n-leitenden Bi2See-Einkristallen zwischen 1,6 und 4,2 K beobachtet. Die Elektronenkonzentrationen lagen im Bereich von etwa 4 × 1017 bis 4 × 1019 cm−3. Stationare Magnetfelder bis 10,5 T standen zur Verfugung. Die Winkelabhangigkeit der Shubnikov-de Haas-Periodenlies eine um die kc-Achse nahezu rotationssymmetrische Form des Fermi-Korpers mit geringer Verzerrung von dreizahliger Symmetrie erkennen. Senkrecht zur kc-Achse fur kc = 0 wurde ein parabolischer e(k⊥)-Verlauf, parallel zur kc-Achse eine zunehmende Nichtparabolizitat gefunden. Erst bei Konzentrationen uber 1019 cm−3 wird die Abweichung der Gestalt des Fermi-Korpers von der eines Rotationsellipsoids wesentlich. Die Zyklotronmasse mc senkrecht zur kc-Achse (B ‖ c) wurde im gesamted Konzentrationsbereich zu 0,124 m0 bestimmt. Fermienergien bis zu 160 meV wurden gefunden. Das Ein-Valley-Modell fur das energetisch tiefste Leitungsband von Bi2Se3 wurde bestatigt.

Reduced pressor responses to stimulation of the locus coeruleus after lesion of the posterior hypothalamus.

Abstract: Electrical stimulation of the locus coeruleus or of the hypothalamic posterior area of cats under pentobarbitone anaesthesia elicited a rise of the arterial blood pressure. Electrocoagulation of the hypothalamic posterior area or its lesion by the injection of ethanol significantly diminished the pressor response to electrical stimulation of the locus coeruleus. The pressor response to electrical stimulation of the area posterior was almost completely abolished after electro-coagulation and strongly inhibited after injection of ethanol. It is suggested that adrenergic neurones ascending from the locus coeruleus to the posterior hypothalamus may be involved in the hypothalamic regulation of the arterial blood pressure.

Dopamine and noradrenaline transport into subcellular vesicles of the striatum.

Abstract: Dopamine storing vesicles were isolated from the caudate nucleus of the pig by differential centrifugation and incubated at various temperatures. The spontaneous release of endogenous dopamine was temperature-dependent. Incubation with 14C-dopamine or 14C(±)-noradrenaline revealed that the vesicles were able to take up catecholamines by two different transport mechanisms; one was dependent on ATP, magnesium and temperature, the other one was independent of ATP and magnesium, and partially dependent on temperature. The Km of the ATP-magnesium-dependent uptake was 1.52×10−6 M for dopamine and 3.45×10−6 M for noradrenaline. Incubation with dopamine increased the dopamine content of the vesicles and diminished the endogenous dopamine by approximately 90%. Addition of ATP and magnesium further increased the dopamine content without influencing the per cent exchange between endogenous and exogenous dopamine. The dopamine uptake at 37°C in the presence of ATP and magnesium was of short duration because of the thermo-lability of the vesicles. (+)-amphetamine competitively inhibited the ATP-magnesium-dependent uptake of dopamine and noradrenaline. Amantadine and desipramine influenced neither the ATP-magnesium-dependent nor the ATP-magnesium-independent uptake of the catecholamines.

Effects of adrenergic drugs on pressor responses to hypothalamic stimulation.

Abstract: The posterior area of the hypothalamus of anaesthetized cats was superfused with artificial cerebrospinal fluid through a push-pull cannula. Electrical stimulation with the non-insulated tip of the cannula elicited a rise of the mean arterial blood pressure. Superfusion of the hypothalamic posterior area with tolazoline or piperoxan caused a dose-dependent inhibition of the pressor responses to electrical stimulation. Labelling of the posterior area with 3H-noradrenaline 2 h before the beginning of the superfusion showed that the inhibitory effect of tolazoline on the pressor responses was accompanied by an increased release of total radioactivity and an enhanced per cent release of 3H-noradrenaline, while that of its metabolites was reduced. Superfusion of the nucleus of the solitary tract with clonidine evoked a dose-dependent inhibition of the pressor responses to electrical stimulation of the ipsilateral hypothalamic posterior area. It is concluded that 1. Alpha-adrenoreceptors are present in the posterior hypothalamus and are involved in the blood pressure rise elicited by its electrical stimulation. 2. A feedback mechanism is present in the hypothalamus which regulates the release of noradrenaline and which is mediated by alpha-adrenoreceptors; inhibition of the regulation of the release of noradrenaline by alpha-adrenoreceptors blocking agents leads to an enhanced release of the neuro-transmitter. 3. Activation of the inhibitory pathways of the nucleus of the solitary tract by clonidine diminishes the pressor response to electrical stimulation of the hypothalamic posterior area. 4. Two adrenergic systems localized in different areas of the central nervous system oppose each other in their regulatory effects on arterial blood pressure.

Organogold‐Chemie, XII. Komplexe von Gold(I)‐ und Gold(III)‐halogeniden mit Thioäthern

Abstract: Einige ein- und zweikernige Komplexe von AuCl und AuCl3 mit mono- und difunktionellen Thioathern wurden hergestellt. Gold(I)-Zentren addieren nur jeweils einen Thioatherliganden, tauschen diesen aber in Losung sehr rasch gegen uberschussigen Liganden aus. Dies gilt auch fur potentielle Chelatliganden. Fur die Gold(III)-Komplexe wird eine ionische Struktur vorgeschlagen. Die Verbindungen sind fur therapeutische Zwecke von Interesse. Organogold Chemistry, XII. Complexes of Gold(I) and Gold(III) Halides with Thioethers A series of mono- and binuclear complexes of AuCl and AuCl3 with mono- and difunctional thioethers have been prepared. In all cases gold(I) centers are adding only one thioether, which in solution is in very rapid exchange with excess ligand, however. This is also true with potential chelating ligands. For the gold(III) complexes an ionic structure is proposed. The compounds are of interest for therapeutic uses.

Über das fetale Gefäßsystem der reifen menschlichen Placenta

Abstract: Die Gefase der Nabelschnur, Chorionplatte, Stammzotten und das Mikrozirkulationssystem des Zottenbaums der reifen menschlichen Plazenta wurden elektronenmikroskopisch untersucht. Die Endothel- und Muskelzellen besitzen auch am Ende der Graviditat alle morphologischen Kennzeichen voller Funktionsfahigkeit. Auffallig sind die zahlreichen myo-endothelialen Verzahnungen und die zahlreichen Kontakte der Muskelzellen untereinander. Sphinkterartige Einrichtungen werden nur an den Verzweigungen der Prakapillaren beobachtet. Gefasnerven fehlen uberall. Moglicherweise kann die Durchstromung der fetalen Placentagefase durch autonome Kontraktion der Gefaswande reguliert werden. — Alle Gefase der Placenta sind elasticafrei. In den Nabelarterien sind elastische Systeme schwach ausgebildet. Eine Elastica interna wird nur in der Nabelvene gefunden. — Das Mikrozirkulationssystem in den Rami und Ramuli chorii sowie den Terminalzotten wird von allen bekannten Endstromeinheiten aufgebaut. Die englumigen Kapillarabschnitte befinden sich vor allem in unmittelbarer Nachbarschaft zum organellenreichen Syncytiophoblast, wahrend die weitlumigen Abschnitte, die moglicherweise die venosen Kapillarstrecken sind, den Epithelplatten anliegen.

Darstellung und Eigenschaften von 2‐Imidazolylsilanen

Abstract: 2-Imidazolylsilane (1–7) werden durch Umsetzung von Trimethylchlorsilan mit Imidazolyllithiumverbindungen und durch Umsilylierungsreaktionen dargestellt. Die C-2–Si-Bindung in diesen Systemen ist sehr reaktiv. Die im Vergleich zu 2-Benzothiazolylsilanen hohere Nucleophilie des Imino-Stickstoffs hat entscheidenden Einflus auf den Reaktionsablauf bei Umsilylierungsreaktionen, Quartarisierungsversuchen und Hydrolysereaktionen. Die Moglichkeiten zur Ausbildung resonanzstabilisierter π-Systeme werden gepruft. Preparation and Properties of 2-Imidazolylsilanes 2-Imidazolylsilanes (1–7) are synthesized by the reaction of trimethylchlorosilane with imidazolyllithium compounds and by trans-silylation reactions. The C-2–Si-bond in these systems is very reactive. The higher nucleophilic character of the imino-nitrogen in comparison to 2-benzothiazolylsilanes has important influence on the reaction path in transsilylation reactions, experiments for quarternisation, and hydrolysis. The possibility for the formation of resonance stabilized π-systems is investigated.

Rassen- bzw. artspezifische Duftbewertung bei der Honigbiene und ökologische Adaptation

Abstract: 1. Lernen Bienen sukzessiv zwei gleich attraktive Dufte, so entscheiden sie sich im Test zu 61,52% fur den zweiten. Ist der zweite Duft attraktiver als der erste, wird er zu mehr, ist er weniger attraktiv, wird er zu weniger als 61,52% gewahlt. Damit ist eine einfache Methode zur Ermittlung der Duftbewertung durch die Honigbiene gefunden. 2. Die Duftbewertung von einem Spektrum von 17 Signalen durch die 3 Rassen der Westlichen Honigbiene (Apis mell. carnica, Apis mell. ligustica, Apis mell. fasciata) und die Ostliche Honigbiene (Apis cerana) ist rassen- bzw. artspezifisch. Volksund individuelle Schwankungen sind unbedeutend. 3. In der Bevorzugung der Dufte sind deutliche Beziehungen zwischen einheimischem Blutenangebot und Habitat der Bienen zu erkennen. 4. Die Duftbewertung ist neben der genetischen Lerndisposition in hohem Mase von dem Lernmotiv (Qualitat der Zuckerlosung) abhangig. Wird ein nicht attraktiver Duft mit 2 mol Zuckerlosung, anschliesend ein attraktiver mit 0,5 mol belohnt, so wird das genetisch nicht attraktive Signal bevorzugt gewahlt. 5. Die Geschwindigkeit des Umschlagens der Wahlen zugunsten des nicht attraktiven Duftes (bei stufenweiser geringerer Belohnung fur das genetisch bevorzugte Signal, konstant 2 mol fur das geringer bewertete) ist wiederum rassen- bzw. artspezifisch. Am schnellsten entscheiden sich die Indischen Bienen fur den weniger attraktiven Duft, danach die Kassen der Westlichen Honigbiene, und zwar in folgender Reihenfolge: Agyptische, Italienische, Krainer Rasse. Die Indische Biene stellt dementsprechend die hochsten Anforderungen an die Konzentration des Nektars, die Rassen der Westlichen Honigbiene stufenweise geringere. 6. Das bedeutet eine Anpassung an das Futterangebot, das qualitatsmasig (entsprechend den schlechteren meteorologischen Bedingungen von Indien uber Syrien, Agypten, Italien nach Mitteleuropa) abnimmt. Dies konnte ein moglicher Weg der Ausbreitung der Honigbiene sein.

Über die Trimethylphosphin‐Komplexe einiger Quecksilber(II)‐Verbindungen

Abstract: Methylquecksilberchlorid bildet mit Trimethylphosphin nur einen ionisch aufgebauten 1:1-Komplex, [CH3HgP(CH3)3]Cl, dessen Liganden bei einem Uberangebot an Phosphin einem raschen Austauschprozes unterliegen. Bei Gegenwart von uberschussigem CH3HgCl wird der Ligand zwischen dem 1:1-Komplex und CH3HgCl ausgetauscht, wie durch NMR-Untersuchungen leicht nachweisbar ist. – Quecksilber(II)-chlorid, -bromid, -jodid, -acetat, -cyanid, -rhodanid und -nitrat lagern demgegenuber bis zu 4 Phosphinmolekule an und gehen dabei teilweise in durch das Gegen-Ion verbruckte, mehrkernige Komplexe, teilweise in Koordinationsverbindungen mit ionischem Strukturprinzip oder in nichtdissoziierte monomere Addukte uber. Die zahlreichen in diesen Systemen existierenden neuen Verbindungen wurden konduktometrisch untersucht und ihre Infrarot-, Raman- und 1H- sowie 31P-NMR-Spektren aufgenommen. Nach diesen Ergebnissen tritt bei den 1:1-Komplexen der Halogenide eine Halogenverbruckung zum Dimeren auf, wahrend die Pseudohalogenide uber CN bzw. SCN oligomerisieren. Die 1:2-Verbindungen enthalten mit Ausnahme des Cyanids die linear konfigurierten [(CH3)3PHgP(CH3)3]2⊖-, die 1:3- und 1:4-Komplexe entsprechend [(CH3)3P]3Hg2⊕- bzw. [(CH3)3P]4Hg2⊕-Ionen. Letztere sind typisch fur Rhodanid und Nitrat. In Losung treten in allen Fallen Ligandenaustauschprozesse auf, die mit zunehmender Ligandenstarke der Gegen-Ionen und mit steigender Zahl der Phosphin-liganden starker begunstigt werden. The Trimethylphosphine Complexes of Some Mercury(II) Compounds Trimethylphosphine reacts with methylmercury chloride to form only a 1:1 complex, [CH3HgP(CH3)3]Cl. However, the ligand is subject to a rapid exchange process in solutions containing excess phosphine. In the presence of excess CH3HgCl the phosphine ligand is exchanged between the 1:1 complex and the CH3HgCl molecule, as can be shown by n.m.r. spectroscopy. – In contrast mercury(II) chloride, bromide, iodide, acetate, cyanide, thiocyanate, and nitrate can add up to four phosphine molecules with formation of gegenion-bridged polynuclear complexes, ionic coordination compounds, or nondissociated adduct molecules. The many new species appearing in these systems have been investigated by conductivity measurements as well as infrared, Raman, 1H- and 31P n.m.r. spectroscopy. According to these results the 1:1 halide complexes exist as halogen-bridged dimers, whereas the pseudohalides oligomerize through the CN and SCN groups, resp. With exception of the cyanide, the 1:2 complexes contain linear [(CH3)3PHgP(CH3)3]2⊕ units, and the 1:3 and 1:4 complexes form [(CH3)3P]3Hg2⊕ and [(CH3)3P]4Hg2⊕ cations, resp. The latter are typical for thiocyanate and nitrate. In all cases ligand exchange processes occur in solution, which are more strongly favored with increasing ligand strength of the gegenion and with an increasing number of phosphine molecules.

Darstellung und Eigenschaften von 2‐Benzothiazolylsilanen

Abstract: 2-Benzothiazolylsilane (2–6) werden durch Umsetzung von Chlorsilanen mit 2-Benzothiazolyllithium und durch neuartige Umsilylierungsreaktionen hergestellt. Die Silicium-Kohlenstoffbindung am Heterocyclus ist sehr reaktiv. Sie wird schon bei Raumtemperatur sehr leicht hydrolysiert, die entsprechenden Imoniumsalze sind instabil, und elektrophile Substitutionsreaktionen in 2-Stellung laufen schon unter sehr milden Bedingungen ab. Die Moglichkeit zur Ausbildung resonanzstabilisierter π-Systeme wird gepruft. Preparation and Properties of 2-Benzothiazolylsilanes 2-Benzothiazolylsilanes (2–6) are synthesized by the reaction of chlorosilanes with 2-benzothiazolyllithium and by new trans-silylation reactions. The silicon-carbon bond at the heterocycle is shown to be very reactive. This is demonstrated by the easy hydrolysis even at room temperature, by the instability of the corresponding imonium salts and by electrophilic substitution in 2-position under mild conditions. The possibility for the formation of resonance stabilized π-systems is investigated.

Die genetische Grundlage der Monogenie bei der Schmeißfliege Chrysomya rufifacies (Calliphoridae, Diptera)

Abstract: Recently in our wild stock of the monogenic blowfly Chrysomya rufifacies a recessive mutation “white” (w) causing white instead of red-brown eyes spontaneously appeared (Fig. 1). This marker gene enabled us to clarify the genetic basis of monogeny in this species. F1 offspring produced by reciprocal crossings between normal (+/+) and white-eyed (w/w) flies were phenotypically wildtype (Table 1). In F2 offspring of female-producing (thelygenic) and male-producing (arrhenogenic) F1 females wildtype and white-eyed flies appeared in the expected 3:1 ratio; in several crossings a slight deviation of this ratio indicated a reduced viability of the w/w individuals (Table 2). Examination of F2 progeny of thelygenic F1+/w females, which had received the w allele from their father, showed that most of the F2+/+ females were thelygenic, whereas most of the F2 w/w females were arrhenogenic; among F2+/w females thelygenic and arrhenogenic individuals occurred in almost equal numbers (Table 3). On the other hand, when F2 offspring of thelygenic F1+/w females which had inherited the w allele from their mother were tested, most of the F2+/+ females turned out to be arrhenogenic and most of the F2 w/w females thelygenic; among F2+/w females thelygenic and arrhenogenic flies also were found in almost equal frequencies (Table 4). the sex-linked inheritance of the factor w following from these results was also confirmed by an analysis of the progeny of thelygenic F1+/w females backcrossed with w/w males. Among the R1 offspring of F1+/w females, which had received the w allele from their father, the +/w females were predominantly thelygenic compared to their predominantly arrhenogenic w/w sisters (Table 5). Analysis of R1 progeny of F1+/w females, which had inherited the w allele from their mother, yielded reciprocal results (Table 6). This mode of incomplete sex-linkage of the mutation “white” observed in C. rufifacies (Figs. 2–5) supports the hypothesis that thelygenic females are heterozygous for a dominant female sex realizer (F') with predetermined sex-determining properties, and that arrhenogenic females as well as the males are homozygous for the recessive allele f (Fig. 6). The recombination frequency between F'/f and the w-Locus was calculated to be 12.72±0.72 per cent.

Kinetics of neutrophilic granulocytes in the blood of rats

Abstract: The kinetics of neutrophilic granulocytes in the blood of rats were investigated using in vivo3H-TdR labelling and autoradiography. The radioactive precursor was administered by single injection, repeated injections at 5 hr intervals and continuous infusion. The appearance of labelled granulocytes in the blood and in the sputum was recorded up to 120 hr after tracer application. In contrast to results after a single injection of 3H-TdR, complete labelling of the blood granulocyte pool was achieved when the DNA precursor was given by continuous infusion or four repeated injections at 5 hr intervals. In the latter experiments, an exponential replacement of unlabelled blood granulocytes by labelled granulocytes could be demonstrated, the mean intravascular half-life being 5·7 hr. This figure is in good agreement with values obtained by isotopic techniques in other mammalian species.

Über den Histochemischen Nachweis der β-Glucuronidase, α-Mannosidase und α-Galactosidase mit 1-Naphthylglykosiden

Abstract: Mit simultanen Azokupplungsverfahren und 1-Naphthylglykosiden als Substraten werden Verteilung und Aktivitat von β-Glucuronidase, α-Mannosidase und α-Galactosidase bei Ratte, Maus und Meerschweinchen untersucht.