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991.
Although intensive care for offspring by both parents is rare in arthropods, it occurs in some species including the beetle Lethrus apterus. According to previous publications, in this species the male collects leaves, which are used by the female to form balls in the underground nest burrow. These balls serve as food for the hatched offspring. Most knowledge about the behavior of this species is based on information collected more than a century ago. Therefore, we investigated above‐ground breeding behavior and the status of nest burrows of this beetle in its natural habitat in Hungary. Our results suggest that contrary to previously documented cases, above‐ground parental care, i.e. the collection of leaves, is done predominantly not by the males but the females. Further research is needed to understand the role of the sexes in parental care in this species and to explain the discrepancy between the previously documented cases and the results we report here.  相似文献   
992.
993.
Four new polyacetylenes, methyl Z,Z-10-acetoxymatricariate, methyl Z,Z-10-hydroxymatricariate, methyl 2(Z)-10-acetoxy-8,9-epoxydecen- 4,6-diynoate and methyl 2(Z)-10-hydroxy-8,9-epoxydecen-4,6-diynoate, were isolated from the composite Chrysothamnus nauseosus. These compounds are naturally-occurring antifeedants of the Colorado potato beetle. The assigned structures rest on their spectroscopic properties as well as chemical interconversions.  相似文献   
994.
995.
The adsorption capacity, the specific adsorptive surface, the lipophilicity and the specific hydrophobic surface of 59 natural and synthetic nucleoside derivatives were determined by means of adsorptive chromatography and reversed-phase thin-layer chromatography for the future application of these molecular parameters in quantitative structure-activity relationship studies. Stepwise regression analysis and principal component analysis proved that each of the physico-chemical parameters has a different information content, and their application in the design of new bioactive derivatives is therefore justified.  相似文献   
996.
997.
Libri novi     
Ohne Zusammenfassung  相似文献   
998.
Summary Based on animal experiments a clinical study with BCG cell wall preparation (CWP) was developed. Patients with head and neck carcinomas stage T1/2N0–2M0 were randomized. One group received surgical treatment only and a second group received preoperative intralesional BCG-CWP. So far 12 patients have been included in each group. After 3 years the CCR (complete cancer remission) in the surgery only group was 39% and that in the preoperative BCG-CWP group, 69% (P=11%). The cumulative proportion of surviving patients was 50% in the surgery only and 73% in the BCG-CWP group (P=21%). BCG-CWP injection was followed by an increase in body temperature and a decrease in peripheral blood lymphocytes. No changes in liver, kidney, or other organ function could be observed after BCG-CWP therapy. Complications and severe secondary effects such as have been described for living BCG were not observed, and significant immunological changes have not been detected so far.  相似文献   
999.
Tibor  Farkas 《Ibis》1969,111(3):281-292
A preference for bushy evergreen undergrowth determines both the local and the general distribution of Cossypha natalensis. The lack of such undergrowth makes equatorial rain-forests unsuitable. Tropical and subtropical evergreen forests provide excellent conditions from this point of view, and they are thus the main habitat type from which C. natalensis has secondarily extended into tropical and subtropical deciduous forests with evergreen undergrowth.
Adult birds remain in or close to their territories throughout the year. First-year birds undertake longer movements during the winter. Breeding territories are relatively small, from 2,500 up to (exceptionally) 10,000 square yards (2,100-8,400 sq. m).
Breeding begins in October. Both sexes build the nest, but only the female incubates. In southern Africa there is one brood a year, and the care of the offspring is protracted. The juvenile moult begins in the third and ends in the sixth month; adults have only one (post-breeding) moult a year.
The begging behaviour of the young is somewhat different from that of most other turdine birds, and is considered to be more primitive. The ontogeny of the adult displays is described as observed in young birds kept in captivity.
The development of vocal behaviour is described. Special attention is given to the different functional forms of the song, and to two of its special features, imitation and a tonal quality termed vox humana.  相似文献   
1000.
The same karyotype which was described previously in A. ventricosa plants from Oran, Algeria was found in plants from Cyprus and in most of the plants from the Apsheron Peninsula, U.S.S.R. This karyotype, which consists of subterminal chromosomes, was designated C v 1 . In the karyotype of about one-third of the Apsheron plants a single pair of submedian chromosomes replaced a pair of long subterminals. This karyotype was designated C v 2 . The chromosomes formed 7II at meiosis in both C v 1 C v 1 and C v 1 C v 2 hybrids regardless of geographic origin. A heteromorphic bivalent was apparent in PMCs in the C v 1 C v 2 hybrids. A pericentric inversion was postulated as the origin of the submedian pair, the C v 2 C v 2 karyotype being the inversion homozygote. The absence of duplication-deficiency gametes was inferred from the good fertility of the heterozygote. Members of the heteromorphic pair were transmitted in equal proportion and the segregates C v 1 C v 1 , C v 1 C v 2 and C v 2 C v 2 were equally fertile; thus the inversion did not handicap reproduction. The small contemporary colonies of A. ventricosa, with peripheral locations and vast distances between them, because of the full homology and interfertility, are considered remnants of a formerly large central population.Contribution No 282 from the Research Station, Central Experimental Farm, Ottawa, Ontario.This paper is dedicated to the memory of Dr. Barna Györffy, whose untimely death on August 5, 1970 ended a distinguished career that was an example of integrity and scholarship to a troubled generation of Hungarian geneticists.  相似文献   
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