Search Results - (Author, Cooperation:A. Feldmann)

2018-09-05

The American Association of Immunologists (AAI)

0022-1767

1550-6606

Medicine

2016-05-21

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

0033-7560

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Electronic Resource

0033-7560

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Electronic Resource

0033-7560

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Electronic Resource

0033-7560

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Electronic Resource

1574-6941

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Electronic Resource

1570-7458

Springer Online Journal Archives 1860-2000

Biology

Zusammenfassung Männchen von Tetranychus urticae wurden mit Röntgenstrahlendosen von 4, 8, 24 and 32 krad bestrahlt (angewendet bei 0–1 d alten adulten jungfräulichen Männchen) und in Paarungskonkurrenz mit l-d alten, nicht bestrahlten Männchen getestet. P-Weibchen wurden—nicht signifikant—häufiger von nicht bestrahlten Männchen begattet; dieser durchgängige Trend war jedoch hoch signifikant, wenn die Ergebnisse aller Versuche zusammengefaßt wurden. Dies zeigt an, daß die Bestrahlung die Paarungskonkurrenzfähigkeit der Männchen verschlechtert. Das Altern von bestrahlten Männchen ergab eine signifikante Abnahme der Paarungskonkurrenzfähigkeit, zum mindesten innerhalb von zwei Tagen nach der Bestrahlung. Wurden Männchen nach 24 krad-Röntgenbestrahlung auf Paarungskonkurrenz in verschiedenem Alter, verglichen mit unbestrahlten entsprechenden Alters, getestet, so zeigte sich, daß die Abnahme der Paarungskonkurrenzfähigkeit von alternden bestrahlten Männchen verursacht wird durch beschleunigtes Altern, das durch die Bestrahlung bewirkt wird.

Abstract Males of Tetranychus urticae Koch were irradiated with X-ray doses of 4, 8, 24 and 32 krad (were applied to 0–1 day-old adult virgin males) and tested in mating competition with one-day-old nonirradiated males. A non-significant excess of parental females were mated to the unirradiated males. This consistent trend in favour of females, mated with unirradiated males was highly significant, when the results of all the experiments were bulked. This indicated that radiation impaired the mating competitiveness of males of T. urticae. Ageing of irradiated males resulted in a significant decrease of male-mating competitiveness at least within 2 days after irradiation. When 24 krad X-rays irradiated males were tested in mating competition at different ages, with unirradiated males of equal age, it was demonstrated that the reduction in mating competitiveness of ageing irradiated males is caused by accelerated agein, due to the irradiation treatment.

Electronic Resource

1570-7458

Anopheles stephensi ; rearing ; water replacement ; automation ; Vallisneria spiralis ; biological water purification

Springer Online Journal Archives 1860-2000

Biology

Résumé Une technique, utilisant des récipients avec des parois latérales perforées (baptisés récipients ouverts) permettant le renouvellement de l'eau et sa purification par une plante aquatique (Vallisneria piralis), est préconisée pour élever la descendance de femelles isolées de A. stephensi. Les performances de cette technique ont été comparées à l'élevage dans des récipients sans parois perforées (récipients clos). L'influence de la densité et de la quantité d'aliments a été examinée dans les deux cas. Dans les récipients ouverts les larves se développent plus vite (deux jours de moins); les mâles se développent plus vite que les femelles, mais cette différence (0,4 j) n'est significiativement pas influencée par les techniques d'élevage ou la densité. Pour une même ponte les adultes provenant des larves se développant le plus vite sont plus gros que ceux qui sont issus des larves les plus lentes. Le récipient ouvert donne une meilleure survie. Un système a été mis au point pour automatiser l'alimentation.

Abstract For rearing progenies of single females of Anopheles stephensi (Liston) (Diptera: Culicidae), a method is proposed using small trays with perforated side walls (called open trays) to allow for water replacement and purification using an aquatic plant Vallisneria spiralis. The performance of this method has been compared with that of rearing single progenies in trays without mesh side walls (closed trays). Effects of larval density and food quantity on rearing performance have been studied in both types of trays. In open trays the larvae developed about 2 days faster than in closed trays. Male larvae developed significantly faster (0.4 days) than females, but this difference was not significantly influenced by method of rearing or larval density. Adults from fast developing larvae were heavier than those emerging from slowly developing larvae from a single egg batch. Open trays gave higher larval survival than closed trays. A system has been developed to automatize larval feeding.

Electronic Resource

1570-7458

Springer Online Journal Archives 1860-2000

Biology

Résumé Des mâles de Tetranychus urticae d'une lignée, homozygote pour une mutation chromosomale structurale (T), ont été mis en compétition avec des mâles “sauvages”. Les mâles T. ne présentaient qu'un léger désavantage dans cette compétition sexuelle. L'effect débilitant de l'âge sur cette compétitivité était le même pour les mâles des deux types. Les tables de vie des deux types ont montré que le taux de multiplication net (RO) de la lignée T était 53,3 soit plus que pour le type sauvage (43,3). Cette différence était due au taux plus élevé de mortalité en fonction de l'âge des femelles adultes de la lignée sauvage. Des différences entre les taux sexuels globaux des deux types ont été aussi observées; la lignée T a produit significativement moins de mâles et plus de femelles que la lignée sauvage. La durée moyenne d'une génération était presque la méme pour les deux lignées (14 jours). Les valeurs du taux intrinsèque d'accroissement (rm) pour les lignées T et sauvage étaient respectivement 0,286 et 0,273. Ces données sur les tables de vie correspondent bien à celles publiées ailleurs pour T. urticae. Les possibilités d'emploi des lignées T pour la lutte génétique, en utilisant les mutations chromosomales structurales comme un “véhicule” de létaux conditionnels, sont examinées.

Abstract Males of Tetranychus urticae Koch (Acarina: Tetranychidae) from a strain, homozygous for a structural chromosome mutation (T) were competed against males from a standard (wild-type) strain for mating of wild-type females. The T-males exhibited only a slight reduction in male mating competitiveness. The debilitating influence of ageing on male mating competitiveness was equal for males of both strains. Life-table studies on both strains showed that the net reproductive rate (RO) of the T-strain was 53.3, which was higher than the RO-value of the standard strain (43.3). This difference was caused by the higher rate of age-dependent mortality of adult females of the standard strain. Also differences between both strains in the total sex-ratio were observed; the T-strain produced significantly fewer males and more females than the standard strain. The mean generation time of both strains was almost equal (14 days). The values of the intrinsic rate of increase (rm) for the T-strain and the standard strain were 0.286 and 0.273, respectively. The life-table data correspond well with those published elsewhere on Tetranychus urticae. The feasibility of T-strains for application in genetic pest control considering the use of structural chromosome mutations as a “transport mechanism” for conditional lethals is discussed.

Electronic Resource

1432-069X

Atopic dermatitis ; Grass pollen ; Allergen-specific T-cells ; Interleukins

Springer Online Journal Archives 1860-2000

Medicine

Summary Since it has been hypothesized that atopic dermatitis represents a cellular immune reaction to exogenous aeroallergens, we investigated whether lesional skin contains allergen-specific T-cells and which lymphokines they might secrete. Using phytohaemagglutinin or grass pollen for the cloning procedure, we established a series of T-cell lines from the skin of two patients. When rechallenged with the allergen, three out of 12 dermal lines which had been cloned with the pollen extract and three out of 20 epidermal lines cloned with PHA were found to proliferate specifically. With one exception, allergen-specific lines were CD4+, CD8−, α/Β receptor +. The reaction pattern to the single components of the grass allergen extract was assessed with the line UH-D3. Further, the proliferative response to Lolium perennis was inhibited by HLA-DR antibody, indicating its dependence on structures of the MHC class II complex. Only one out of four CD4+ allergen-reactive lines secreted considerable interferon-γ activity but all secreted interleukin-4. The relative predominance of IL-4 points to a possible role of skin-derived T-cells in the synthesis of IgE. The identification of allergenspecific T-cells in lesional skin of patients with atopic dermatitis is consistent with the hypothesis that their dermatitis represents a T-cell-mediated immune reaction.

Electronic Resource

1432-1246

Springer Online Journal Archives 1860-2000

Medicine

Zusammenfassung Die Untersuchungsbefunde bestätigen die Ansicht von verschiedenen Autoren, daß bei untertage beschäftigten Bergarbeitern eine leichte Abweichung der pulmonalen Funktion vom Normalen festzustellen ist. Die beschriebenen Veränderungen sind, was ihre funktionelle Bedeutung anlangt, gering. Zu dem in den letzten Jahren immer wieder geäußerten Verdacht, daß eine chronische Staubexposition zu einer unspezifischen Staublunge mit schwereren Ausfallserscheinungen und zur chronisch obstruktiven Bronchitis führt, ergab die vorliegende Untersuchung keinen Anhalt. Nach unserem heutigen Wissen handelt es sich um funktionelle Anomalien, die auf dem Boden einer vermehrten bronchialen Schleimhautsekretion entstehen, wobei vielleicht auch im höheren Alter die Ausbildung eines centroacinären Emphysems eine Rolle spielen mag. Der pulmonale Gasaustausch und die Ventilierbarkeit der Lunge werden hierdurch nicht wesentlich beeinflußt.

Electronic Resource

1617-4623

Springer Online Journal Archives 1860-2000

Biology

Summary Two genes involved in the enzymatic conversion of D-alanine to pyruvate are described, alnA and alnR. The alnA gene, located between ara and leu, is probably the structural gene for alaninase. The alnR gene, which can be cotransduced with thr but not with leu, could be demonstrated to be a regulatory gene with the aid of a mutation resulting in permanent repression and a thermosensitive revertant of this mutation restoring inducibility at 28°C, but not at 42°C.

Electronic Resource

1439-6327

Springer Online Journal Archives 1860-2000

Medicine

Zusammenfassung 1. Bei der Arbeit am Ergographen, die mittelselektrischer Reizungen vollbracht wird, ruft eine 1 Minute lange Pause, welche mit einer Unterbrechung des Blutstromes im arbeitenden Arm, und zwar zur Zeit der Senkung der Kontraktionshöhen in das Ergogramm eingeschaltet wird, gar keine nachfolgende Restitution (keine Steigerung der Höhe der Muskelkontraktionen) hervor. 2. Bei der Arbeit am Ergographen, die auswillkÜrlichen Kontraktionen der Muskeln besteht, ergibt eine Pause mit Hemmung des Blutstromes die gleiche Wirkung wie in 1. 3. Bei der genannten Art von Muskelarbeit gelingt es nicht, einen depressorischen propriozeptiven, durch die Muskel auf die Nervenzentren ausgeÜbten Einfluß festzustellen, der die Restitution des Nervenimpulses hätte maskieren können.

Electronic Resource

1573-6857

Springer Online Journal Archives 1860-2000

Biology

Electronic Resource

1573-6857

Springer Online Journal Archives 1860-2000

Biology

Abstract Three different strains, homozygous for a radiation induced structural chromosome mutation (T), exhibiting negative hererosis, were tested for their ability to displace the standard (wild-type) karyotype from experimental populations. The experimental populations were initiated by mixing fertilized females of both a T strain and the standard strain at different ratios. Two of the T strains showed the ability to displace the standard karyotype if the initial frequency of the T karyotype was at least 0.65. The additional release of T males into the experimental population accelerated considerably the process of displacement of the standard karyotype, especially if the initial T karyotype frequency was 0.65. A computer model for simulating the process of population displacement in Tetranychus urticae was developed. The model accounts for variation in developmental time and for the age dependency of variables related to fitness. The simulations showed a good correlation with the experimental results. A system analysis on the sensitivity of the model output to varying different population parameters demonstrated that especially the relative number of males produced by a T strain and the female developmental rate were of significant importance to the population displacement ability of a T strain. The negative influence of genetic markers on general fitness and various aspects of practical application of the method are discussed.

Electronic Resource

1618-2650

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Electronic Resource

1618-2650

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Electronic Resource

0075-4617

Chemistry ; Organic Chemistry

Wiley InterScience Backfile Collection 1832-2000

Chemistry and Pharmacology

Electronic Resource