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371.
Lindsey R. Milbrath Maurice J. Tauber Catherine A. Tauber 《Behavioral ecology and sociobiology》1994,35(2):85-90
Field and laboratory studies compared two features of larval behavior in a pair of predacious sisterspecies of green lacewings: one (Chrysopa slossonae) a specialist on a single species of colonial aphids (the woolly alder aphid) that occur on branches and trunks of alder trees, the other (C. quadripunctata) a general aphid feeder whose primary prey is dispersed on foliage of diverse types of trees. First, a few hours after hatching, larvae of the two species develop significantly different phototactic responses; the differences correspond well with the spatial distributions of their prey. Most C. slossonae exhibited negative phototaxis, a response that helps move hatchlings inward on alder trees toward the woolly alder aphid colonies, whereas most C. quadripunctata hatchlings showed positive orientation to light, a response that tends to keep them in tree canopies with their prey. Second, in greenhouse experiments, a significantly greater proportion of C. slossonae larvae (second instars) molted within woolly alder aphid colonies and remained with the aphids than did C. quadripunctata larvae. These differences indicate that the specialist larvae have evolved a high degree of behavioral fidelity to their prey. However, larvae (second instars) of the two species that were released near ant-tended woolly alder aphid colonies in the field had similar recovery (= survival) rates. Consequently, natural selection may not act on behavioral traits that influence larval fidelity to prey during the late second and early third instars. 相似文献
372.
Reliance on self-assessed training needs for input into decisions regarding training participation and design is increasingly common. Previous study results indicate that perceptions of training utility influence these self-assessments. In a sample of 380 managers and supervisors, this study found that training self-efficacy and managerial support positively influenced perceptions of training utility, while educational level was negatively associated with these perceptions. In addition, training utility perceptions and span of control both directly and positively influenced reported need for training in management skills. Implications for both research and practice are discussed. 相似文献
373.
Samples have been collected from major horizons of 34 podzol profiles distributed throughout Scotland, all developed from granite or granitic tills and under Calluna moorland. the pH in water and calcium chloride pastes, exchangeable cations and cation exchange capacity, and extractable aluminium of the soils collected have been measured, and the results studied in relation to reported atmospheric deposition of H+, non-marine sulphur and nitrate. for all horizons, significant positive correlations were found between soil pH and rainfall mean pH, as might be expected when the critical load of H+ deposition is exceeded. Acidifying pollutant deposition also apparently increased soil extractable aluminium concentrations in the B and C horizons. However, exchangeable base cation concentrations tended to increase, rather than decrease, with increasing precipitation acidity. This effect was attributed to increases in biogeochemical cycling of base cations, increases in leaching inputs of base cations from overlying A/E horizon soils, and increases in the inputs of base cations leached from upslope. the results suggest that the simple steady state mass approach to the quantification of critical loads, as often applied, may be an oversimplification. 相似文献
374.
In the first of two articles presenting the case for emotional intelligence in a point/counterpoint exchange, we present a brief summary of research in the field, and rebut arguments against the construct presented in this issue. We identify three streams of research: (1) a four‐branch abilities test based on the model of emotional intelligence defined in Mayer and Salovey (1997); (2) self‐report instruments based on the Mayer–Salovey model; and (3) commercially available tests that go beyond the Mayer–Salovey definition. In response to the criticisms of the construct, we argue that the protagonists have not distinguished adequately between the streams, and have inappropriately characterized emotional intelligence as a variant of social intelligence. More significantly, two of the critical authors assert incorrectly that emotional intelligence research is driven by a utopian political agenda, rather than scientific interest. We argue, on the contrary, that emotional intelligence research is grounded in recent scientific advances in the study of emotion; specifically regarding the role emotion plays in organizational behavior. We conclude that emotional intelligence is attracting deserved continuing research interest as an individual difference variable in organizational behavior related to the way members perceive, understand, and manage their emotions. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
375.
In South Africa an intensive reform process to democratize policy, legislation and related institutions in the country commenced after the first democratic elections in 1994. While environmental law reform includes active public participation and equity principles, it is proposed in this paper that ecological modernization dominates current environmental assessment practice. This paper presents a Social Impact Assessment (SIA) of a proposed landfill on the periphery of Durban, where large informal settlements and peri-urban areas exist as a relic of apartheid planning. The methodology of the SIA was explicitly designed within a framework of social justice to include poor and marginalized people, who remain excluded from environmental decision making despite the promise of democratic equality. The study claims to deepen democratic practice by demonstrating that alternative methodologies can be designed to include the interests of ‘invisible stakeholders’ in environmental assessments despite the dominance of ecological modernization in the implementation of environmental law and policy. 相似文献
376.
Macroinvertebrate biomonitoring in intermittent coastal plain streams impacted by animal agriculture
Little attention has been given to the ecology of intermittent coastal plain streams in the southeastern United States, and it is not known whether available macroinvertebrate biomonitoring methods reliably detect degradation in these streams. This study compared differences in biomonitoring metrics between reference and agricultural streams, and between the flow period (January-April) and the intermittent flow period (May-December). Percentages of crustaceans, isopods, and Ephemeroptera-Plecoptera-Trichoptera (EPT) were significantly higher at the reference site than the two most impacted sites during the flow period, probably resulting from the abundance of leaf litter and lower temperatures. During this same period, the agriculturally impacted sites had a significantly higher percentage of dipterans--a group that thrives in the silty, nutrient-rich waters. Four metrics (percent Crustacea, Isopoda, Diptera, and EPT) had no overlap between values for the most impacted and the least impacted sites during the flow period, but no metrics were able to detect more discrete differences among sites. Sites were physically and biologically similar during the intermittent period when natural stresses (i.e., stagnant water, high temperatures, low dissolved oxygen) were high, with many metrics, such as percentages of dominant family, burrowers, chironomids, and dipterans becoming similar at all sites. Our findings indicate that development of a better understanding of invertebrate fauna in reference conditions and of the natural variation in intermittent streams is necessary to develop effective biomonitoring programs for these systems. 相似文献
377.
Catherine Holt Norman D. Yan 《Ambio-人类环境杂志》2003,32(3):203-207
尽管大气中SO2- 4的沉降减少,地表水的酸度也因此降低,但尚未记录到广泛的生物从酸化中恢复过来.本文通过考察1971~2000年间加拿大安大略省基拉尼公园的46个湖泊甲壳类浮游动物种的丰富度(物种数目)和组成的时间变化趋势,来估计由于水质有了重大改善即pH现在>6后湖泊中生物的恢复程度,并与其他两组(从未酸化的湖泊和仍然酸化的湖泊[pH<6])作比较.在这三组湖泊中,物种丰富度的时间趋势无法加以区别,物种丰富度的变化也不能说明恢复的程度.对比之下,在pH值增加到6以上的湖泊中,其浮游动物群落的组成(以物种多度的多变量指数表征)则有所变化,从"损害"状态返回到了中性湖泊的典型状态.在酸性湖泊也记录到浮游动物组成有某些恢复.虽然仍为酸性,这些湖泊的pH水平已经升高.基拉尼省公园里甲壳类浮游动物恢复的程度和速度为北美和欧洲其他酸化地区的将来预示了光明的前景. 相似文献
378.
Eric Jauniaux Catherine Donner Christine Thomas Jacques Francotte Frédéric Rodesch Freddy E. Avni 《黑龙江环境通报》1988,8(8):557-563
Prenatal diagnosis of cord defects by means of ultrasound examination is possible and highly accurate. Although this is a rare pathological finding, we report two cases in which umbilical cord pseudocysts were associated with trisomy 18. These observations underscore the need of umbilical blood sampling for establishing the karyotype in fetuses with such umbilical cord anomalies and the importance of careful examination of placentas and infants born with such defects. 相似文献
379.
Catherine G. Palmer Judith H. Miles Patricia N. Howard-Peebles R. Ellen Magenis Shivanand Patil Jan M. Friedman 《黑龙江环境通报》1987,7(8):551-555
Data pooled from contributors to a Registry for Cytogenetic Abnormalities and PKU (ReCAP) shows an unbalanced chromosome abnormality rate of 27 per cent (29 fetuses) for 107 fetuses with ultrasonically diagnosed fetal anomalies. Of the abnormal, 12 were trisomic, 6 were monosomy X and 6 were structural abnormalities, 4 were mosaics and one triploid. 相似文献
380.