Der Einfluß eines Gestagens und eines Östrogens auf das Längenwachstum der Tubuli seminiferi beim Zwergschwein

Contents: 16 male mini-pigs were divided into 3 groups (group A: n = 5; group B: n = 5; group C: n = 6 individuals). At an age of 60 and 75 days the 5 individuals of group A were given subcutaneous injections of 50 mg chlormadinon-acetate each time; the 5 animals of group B received 20 mg estradiol valerianate intramuscularly in the same schedule as group. A 6 boars served as controls (group C). All animals were sacrifized at an age of 180 days, their testes removed and examined.
2. The weight of the testes in group A was significantly lower than in the control group (P ≤ 0,05). The weight of the germinal epithelium, determined indirectly by means of the area it is occupying in the histological slide, was significantly lower in groups A and B in comparison to the controls (P ≤ 0.05 resp. P ≤ 0.01).
3. The diameter of the tubules was slightly greater in group A than in the other groups (P ≤ 0,05). With 791 m in group A and 982 m in group B, the length of the tubules proved to be significantly shorter than in the control group with 1560 m (P ≤ 0,01). In none of the groups spermatogenesis was impaired.
4. The growth of length of the tubules seems to be a more sensitive criterion than spermatogenesis for the determination of the adverse influence of steroids on the adenohypophysis, especially in immature individuals. A certain difference in the control of the 1 functions "spermatogenesis" and "growth of length of the tubules" by gonadotropins must be taken into consideration.     

Tiefgefrierung von Schafbocksperma in Pelletform mit unterschiedlichen Abkühlverfahren vor dem Einfrieren

Inhalt Im “split-sample-Verfahren” wurden insgesamt 24 Ejakulate von 3 Schafböcken entweder mit einem Tris-Verdünner oder einem modifizierten Raffinose-Eidotter-Glyzerin-Verdünner verdünnt und gleichmäβig von + 20 °C auf + 5 °C abgekuhlt. Ein Teil des verdünnten Samens wurde ohne Adaption sofort bei dieser Temperatur pelletiert, die restlichen 2 Teile auf 0 °C bzw. – 5 °C abgekühlt und anschlieβend, ebenfalls ohne Adaption, eingefroren. Aufgetaut wurden die in flüssigem Stickstoff gelagerten Pellets ohne Verdünnerzusatz auf Teflon, mit einem Trisverdünner oder mit “B. G. milk”. Beide Verdünner eigneten sick gleich gut für die Tiefgefrierkonservierung von Schafbocksperma. Die Motilität des Spermas aller drei Böcke betrug nach dem Auftauen 49,8; 53,5 und 55,4 % (Differenzen P 0.05). Die besten Ergebnisse erbrachte dos Auftauen der Pellets in Trislösung oder “B. G. milk”. Contents (Deep-freezing of ram semen in pellet form with different cooling schedules before freezing). Using the “split-sample” method a total of 24 ejaculates from 3 rams were diluted either with Tris-diluent or with a modified raffinose-egg yolkglycerin diluent and cooled Jrom i. 20°C to + 5°C. One portion of the difuted semen was pelfeted immediately at this temperature without adaptation. The remaining 2 portions were cooled to 0°C and - 5°C respectively and frozen without adaptation. The pellets were stored on Teflon in liquid nitrogen and then thawed with Tris-diluent of “B.G. milk”. Both diluents used were equally suitable for deep-freezing of ram semen. The motility of the sperm of the 3 rams after thawing was 49.8%, 53.5% and 55.4% (P < 0,05). The best results were obtained by thawing the pellets in Tris-solution “B.G. milk”.     

Redistributing work in aging Europe

As Europe ages, the proportion of people who work will decline unless older individuals remain in the labor force. Such reform could be part of a more general redistribution of work. If a greater share of the population worked, then the average number of hours worked per week could be reduced. This could particularly help younger people and increase Europe's low birth rates. The challenges facing Germany, Europe's most populous country, are highlighted, but statistics are also given for five other European countries and, for comparison, the United States. Social science research is needed to provide policy-relevant knowledge about life-course options.     

Orientierende Versuche zur Kombination von Pheromonfallen mit dem insektenpathogenen PilzBeauveria bassiana (Bals.) Vuill. gegen die Borkenkäferartlps typographus L. (Col., Scolytidae)

Zusammenfassung In ersten, orientierenden Versuchen wurde die Wirkung des tschechischenBeauveria bassiana-Präparates Boverol allein und in Kombination mit Pheromonfallen auf die Mortalität und das Brutverhalten des Buchdruckers,Ips typographus, untersucht. Pathogenitätstests ergaben eine Verpilzungsrate von 88,0 bis 96,7%. Wurden Käfer nach der oberflächlichen Kontamination sofort zur Brutablage an frische, berindete Fichtenstücke gesetzt, so betrug die Reduktion der Brutleistung gegenüber der Kontrolle nur etwa 23 bis 29%. Bei der geschlüpften F₁-Generation von kontaminierten Altkäfern konnten keine Unterschiede zu den vergleichbaren Jungkäfern aus der unbehandelten Kontrolle festgestellt werden. Eine Übertragung des Pilzes vom Altkäfer auf den Jungkäfer fand nur in Ausnahmefällen statt. Im Freiland wurde die Wirkung einer Kombination von Pheromonfalle mitB. bassiana getestet, wobei das Einbohrverhalten und die Brutleistung der Käfer in einer darunter eingekäfigten Fichtenrolle überprüft wurden. Die Zahl der Einbohrlöcher war in der BOVEROL-Variante um etwa 15% verringert, die F₁-Generation jedoch um nahezu 60%. Mögliche Einsatzstrategien vonBeauveria bassiana mit Hilfe von Pheromonfallen beiIps typographus werden erörtert.

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Preliminary trials on the combination of pheromone traps with the entomopathogenic fungusBeauveria bassiana (Bals.) Vuill. against the bark beetle speciesIps typographus L. (Col., Scolytidae)

In first, preliminary experiments, the efficacy of the CzechBeauveria bassiana product Boverol alone and in combination with pheromone traps on the mortality and the breeding behavior of the bark beetle,Ips typographus, was investigated. Pathogenicity tests resulted in a mortality due to the fungus of 88.0 to 96.7%. When the beetles were given directly after superficial contamination on fresh spruce pieces with bark, the reduction of the breeding efficacy was 23 to 29% compared to the untreated control. No differences between the hatched beetles from the F1-generation of contaminated beetles and those of the untreated control beetles were observed. A transfer of the fungus from the parent beetle to the young beetle was noticed only in a few cases. In the field, the efficacy of a combination of a pheromone trap withB. bassiana was tested. The number of bore holes and the breeding was measured using a caged spruce log. In the combination, the number of bore holes was reduced by 15%, but the F1-generation nearly by 60%. Possible strategies for the use ofB. bassiana in combination with pheromone traps againstIps typographus are discussed.

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Aging. It's never too late

When organisms as diverse as yeast and rodents are subjected to a restricted diet, they live longer. The good news is, according to Vaupel, Carey, and Christensen in their Perspective, that switching to a restricted diet at any age can yield the benefit of increased longevity--at least in flies (Mair et al.).