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461.
Infant babbling in humans and a few other primates plays an important role in allowing the young to practice the adult vocal repertoire during early behavioral development. Vocalizations uttered during babbling resemble, to some degree, the acoustic structure of adult vocalizations and are often produced in long bouts independent of any social context. Similar behavior, termed subsong or plastic song, is known from a variety of songbirds. Here, we show that pups of the sac-winged bat (Saccopteryx bilineata), a species with an unusually large vocal repertoire, produce renditions of all known adult vocalization types during bouts of vocalizations, which appear to be independent of a distinct social context. Babbling occurs in pups of both sexes, even though only adult males, not females, utter all different vocalization types produced in infancy. To our knowledge, this is the first evidence of babbling in a nonprimate mammal and suggests that infant babbling may be necessary for the ontogeny of complex vocal repertoires. 相似文献
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Males of the sac-winged bat, Saccopteryx bilineata, actively fill their propatagial sacs with secretions from the genital region, the gular gland, urine and saliva. From our
observations and those of Starck we deduce that propatagial sacs in S. bilineata do not have a glandular function, but are instead organs for the storage and display of odours. In addition to the already
known “salting” and hovering behaviour of male S. bilineata, we describe in detail how odour is fanned to roosting individuals during the complex, stereotypic hovering displays. S. bilineata males also coat the fur of their backs with saliva using the wing tip and might scent-mark territory boundaries. “Yawning”
may represent a visual as well as an olfactory cue. Odour seems to play an important role in the social communication of S. bilineata and in other emballonurids, as revealed by the broad distribution of wing sacs in this family. S. bilineata males display odour during energetically costly hovering flights in front of females. We demonstrate that the number of hovering
displays increases with harem size. The mating effort of S. bilineata males comprises a multimodal signalling behaviour. Although males defend harem territories in which females gather, females
seem to be able to choose the father of their progeny freely among the males of a colony. This may have led to the evolution
of the complex mating displays by male S. bilineata.
Received: 9 December 1998 / Received in revised form: 6 May 1999 / Accepted: 13 June 1999 相似文献
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466.
Industrial ecology: engineered representation of sustainability 总被引:1,自引:0,他引:1
Industrial ecology is a relatively new field of research and academic study and is well established in North America and in
several Asian countries. However, it has not yet received the attention it deserves in some other important parts of the industrialized
world, including Germany. This paper may contribute to a better appreciation of industrial ecology as a tool in the process
of sustainable development of economies, social systems, and of aquatic and terrestrial biotopes under the pressure of rapidly
changing conditions triggered by global warming and urban growth. For this reason, methods are needed to quantify the successful
application of industrial ecology measures. The “Integrated Sustainability Triangle” is introduced as a promising new possibility
of quantification and monitoring. It enables justification of the contributions industrial ecology can make to sustainable
development. The aggregation of individual economic contributions is assumed to create an overall impetus to the entire industrial
sector including the sector of environmental engineering. Thus, the potential of industrial ecology is discussed from the
macro-economic and the engineering perspective using the concept of sustainable development as a guiding principle. But the
authors come to the conclusion that finding solutions to the pressing problems of our time requires more than collaboration
of economy and engineering. It requires joint efforts of the whole spectrum of scientific disciplines in close collaboration
with industrial and political stakeholders. 相似文献
467.
Fetal lymphangiomas are rare congenital anomalies of the lymphatic system most commonly presenting in the head and neck. Cystic abdominal lymphangiomas are more rare with only a few cases reported prenatally. We report a case of a prenatally detected abdomino-perineal lymphangioma that mimicked the more fatal prenatally detected sacrococcygeal teratoma (SCT), which resulted in one caregiver suggesting termination of the pregnancy. This case demonstrates the importance of carefully considering the differential diagnosis of fetal abdomino-perineal masses when counseling parents. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
468.
Maternal uniparental disomy (UPD) 20 was found in a 35-month-old girl, the product of a pregnancy complicated by a prenatal diagnosis of mosaic trisomy 20. Phenotypic abnormalities included pre- and postnatal growth failure, microcephaly, minor dysmorphic features and psychomotor developmental delay. Chromosomal analysis on cord blood revealed only a normal 46,XX karyotype. Microsatellite analysis of 27 chromosome 20 loci confirmed maternal UPD for all 11 informative markers. Maternal heterodisomy was detected in two and maternal isodisomy in three loci. In the remaining six loci, a non-informative maternal UPD pattern was displayed, as mother and proband are homozygous for the same allele. To our knowledge this is the first reported case of maternal disomy 20 with normal karyotype ascertained by a mosaic trisomy 20 pregnancy. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
469.
This study evaluates the acidification status and trends in streams of forested mountain ranges in Germany in consequence of reduced anthropogenic deposition since the mid 1980s. The analysis is based on water quality data for 86 long-term monitored streams in the Ore Mountains, the Bavarian Forest, the Fichtelgebirge, the Harz Mountains, the Spessart, the Black Forest, the Thuringian Forest, and the Rheinisches Schiefergebirge of Germany and the Vosges of France. Within the observation period, which starts for the individual streams between 1980 and 2001 and ends between 1990 and 2009, trends in chemical water quality were calculated with the Seasonal Mann Kendall Test. About 87% of the streams show significant (p < 0.05) negative trends in sulfate. The general reduction in acid deposition resulted in increased pH values (significant for 66% of the streams) and subsequently decreased base cation concentrations in the stream water (for calcium significant in 58% and magnesium 49% of the streams). Reaction products of acidification such as aluminum (significant for 50%) or manganese (significant for 69%) also decreased. Nitrate (52% with significant decrease) and chloride (38% with significant increase) have less pronounced trends and more variable spatial patterns. For the quotient of acidification, which is the ratio of the sum of base cations and the sum of acid anions, no clear trend is observed: in 44% of the monitored streams values significantly decreased and in 23% values significantly increased. A notable observation is the increasing DOC concentration, which is significant for 55% of the observed streams. 相似文献
470.