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We tested the hypothesis that the weight lost by female Great and Blue Tits Parus major and P. caeruleus while raising their first brood influences their ability to start a second brood. The evening weight of female parents was recorded when the nestlings were 5 and 13 days old, in different years and habitats. Several predictions were tested: (1) both species lose weight while raising nestlings and Great Tit females which start a second brood lose less weight than females which do not; (2) differences in the average weight lost between years and areas correlate with differences in the proportion of second broods; (3) the relative weight loss in Blue Tits, which only rarely undertake second broods, is higher than in Great Tits in which second broods are more common. Other factors also are related to the probability of undertaking a second brood: more second broods are undertaken by more successful females, adult females and females that lay earlier.
The comparison of Great and Blue Tits suggests that the two species use different reproductive strategies. 相似文献
The comparison of Great and Blue Tits suggests that the two species use different reproductive strategies. 相似文献
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JORDI DE GIBERT ROSA DOMÈNECH JORDI MARTINELL 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2004,37(4):429-437
Animal bioerosion trace fossils upon mineral substrates are analyzed from the point of view of the Seilacherian ethological classification. Several of the currently accepted ethological classes: cubichnia, fugichnia, repichnia, fodinichnia, agrichnia, calichnia and aedificichnia are not represented in these substrates. This fact points out a lower behavioral diversity of hard substrate trace fossils when compared with soft sediment trace fossils. Bioerosion traces can be classified in just five classes: domichnia, pascichnia, equilibrichnia, praedichnia and fixichnia. Fixichnia is here erected to gather superficial etching scars resulting from the anchoring of fixation of sessile epiliths by means of a soft or skeletal body part. Praedichnia and fixichnia are exclusive of the bioerosion realm. 相似文献
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Abstract. Gravistimulation was investigated as a potential and unwanted component in the interpretation of physiological investigations on plants. Using both seedlings and mature sunflower plants, two situations are described where gravistimulation contributes significantly to the outcome of an experiment not initially designed to include this parameter. The number of adventitious roots formed in derooted seedings decreased when the tops of the plants were allowed to bend over under their own weight, and the effect correlated positively with the rate of ethylene production by non-vertical stems. In droughted mature plants, and increase in leaf and stem ethylene caused by water stress was supplemented by additional ethylene produced in the lower halves of stems. Drought had caused these stem tissues to wilt, become gravistimulated, and thus produce more ethylene. Other situations in which gravistimulated ethylene production and its physiological consequences are likely to be complicating factors in experiments are discussed. It is concluded that procedures that unnecessarily place experimental material in non-vertical orientations should be avoided. 相似文献
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Soares TN Melo DB Resende LV Vianello RP Chaves LJ Collevatti RG Telles MP 《American journal of botany》2012,99(2):e72-e73
? Premise of the study: Microsatellite markers were developed for the population genetic analyses of the neotropical tree Dipteryx alata (Fabaceae). ? Methods and Results: Microsatellites were developed from a genomic shotgun library. Polymorphism at each microsatellite loci was analyzed based on 94 individuals from three populations. Eight loci amplified successfully and presented one to 10 alleles, and expected heterozygosities ranged from 0.097 to 0.862. Four loci also amplified in Pterodon emarginatus and presented similar polymorphism. ? Conclusion: The eight microsatellite primer pairs are potentially suitable for population genetic studies and successfully amplified in another Fabaceae species. 相似文献
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S. B. do Nascimento Tavares N. L. A. de Sousa E. J. C. Manrique Z. B. P. de Albuquerque L. C. Zeferino R. G. Amaral 《Cytopathology》2008,19(4):254-259
Objective: To evaluate the performance of rapid pre-screening (RPS) as a method of internal quality control in the cytopathological examination of cervical smears for cervical cancer screening.
Methods: The sample consisted of 6135 cervical smears submitted to RPS and routine screening (RS) methods. The smears classified as negative in RPS and RS were considered final diagnoses, and were not, therefore, submitted to any additional review. The smears identified as suspect or unsatisfactory according to RPS were analysed separately by two different cytologists irrespective of the diagnosis reached in RS. Smears considered abnormal or unsatisfactory at RS were also reviewed. When both cytologists issued concordant diagnoses, this was considered the final diagnosis. Discordant results were analysed by a third cytologist and a consensus meeting was held to define the final diagnosis.
Results: Taking abnormalities detected by RS as the denominator, RPS had a sensitivity of 63.0% for the detection of all abnormal smears and 96.7% for high grade squamous intraepithelial lesion (HSIL). When compared with the final diagnosis, sensitivity of RPS for all abnormal smears was 74.9% and for HSIL 95.0%. Of the 529 abnormal smears confirmed in the final diagnosis, 2.15% were detected only by the RPS.
Conclusion: RPS is an effective alternative method of internal quality control with high sensitivity for the detection of more severe lesions. It also permits monitoring of the laboratory rate of false-negative results, and allows constant evaluation of the performance both of the pre-screening and RS cytologists. 相似文献
Methods: The sample consisted of 6135 cervical smears submitted to RPS and routine screening (RS) methods. The smears classified as negative in RPS and RS were considered final diagnoses, and were not, therefore, submitted to any additional review. The smears identified as suspect or unsatisfactory according to RPS were analysed separately by two different cytologists irrespective of the diagnosis reached in RS. Smears considered abnormal or unsatisfactory at RS were also reviewed. When both cytologists issued concordant diagnoses, this was considered the final diagnosis. Discordant results were analysed by a third cytologist and a consensus meeting was held to define the final diagnosis.
Results: Taking abnormalities detected by RS as the denominator, RPS had a sensitivity of 63.0% for the detection of all abnormal smears and 96.7% for high grade squamous intraepithelial lesion (HSIL). When compared with the final diagnosis, sensitivity of RPS for all abnormal smears was 74.9% and for HSIL 95.0%. Of the 529 abnormal smears confirmed in the final diagnosis, 2.15% were detected only by the RPS.
Conclusion: RPS is an effective alternative method of internal quality control with high sensitivity for the detection of more severe lesions. It also permits monitoring of the laboratory rate of false-negative results, and allows constant evaluation of the performance both of the pre-screening and RS cytologists. 相似文献
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Predators marked with chemical cues from one prey have increased attack success on another prey species 下载免费PDF全文
GEORGE BROUFAS PAULIEN DE JONG ERNESTINA AGUILAR‐FENOLLOSA ALEXANDRA REVYNTHI MAURICE W. SABELIS ARNE JANSSEN 《Ecological Entomology》2015,40(1):62-68
1. To reduce the risk of being eaten by predators, prey alter their morphology or behaviour. This response can be tuned to the current danger if chemical or other cues associated with predators inform the prey about the risks involved. 2. It is well known that various prey species discriminate between chemical cues from predators that fed on conspecific prey and those that fed on heterospecific prey, and react stronger to the first. It is therefore expected that generalist predators are more successful in capturing a given prey species when they are contaminated with chemical cues from another prey species instead of cues from the same prey species. 3. Here, a generalist predatory mite was studied that feeds on thrips larvae as well as on whitefly eggs and crawlers. Mites were marked with cues (i.e. body fluids) of one of these two prey species and were subsequently offered thrips larva. 4. Predators marked with thrips cues killed significantly fewer thrips than predators marked with whitefly cues, even though the predator's tendency to attack was the same. In addition, more thrips larvae sought refuge in the presence of a predatory mite marked with thrips cues instead of whitefly cues. 5. This suggests that generalist predators may experience improved attack success when switching prey species. 相似文献