The impact of warming on the appearance of furunculosis in fish of the James Bay region,Quebec, Canada

A regional climate change impact assessment was conducted which investigated the timing of the first appearance of furunculosis caused by the bacterium, Aeromonas salmonicida, in fish of the Ouje-Bougoumou region of northern Quebec, Canada. Historical data were used to assess whether there was a temporal relationship between increased temperatures (observed climate data) and the appearance of furunculosis (traditional environmental knowledge was used to provide context). To project future impacts of climate change, climate models and lake models were used. Regression analysis revealed a significant, positive temporal trend in mean air temperature. The temperature range conducive to A. salmoncida survival coincided with the first appearance of furunculosis. In addition, it is predicted that lake temperatures will remain suitable for the presence of A. salmonicida into the future; it is likely that the disease will persist throughout the twenty-first century. Climate change appears to be a factor explaining the onset of furunculosis; however, other factors/stressors cannot be discounted, such as, the effects past mining activities near the lakes of the Ouje-Bougoumou region have had on the body burden of contaminants in the fish (and the potential effects on the fish immune system).     

Unemployment and the backward incidence of pollution control

This paper reexamines the backward incidence of pollution control using duality theory for a two-sector general equilibrium model in which the economy experiences large-scale unemployment and perfect capital mobility with a sector-specific rigid wage in the polluting sector. In this context it is shown that with stricter pollution controls the wage rate in the nonpolluting sector rises while the common rental rate falls. In addition, stricter pollution controls are shown to have an uncertain impact on national income.     

Echolocation call design and limits on prey size: a case study using the aerial-hawking bat Nyctalus leisleri

The echolocation calls used by Nyctalus leisleri during search phase in open air space are between 9 and 14 ms long, with the peak energy between 24 and 28 kHz. The pulses are shallowly frequency-modulated with or without an initial steep frequency-modulated component. The diet consists primarily of small flies (Diptera), including many chironomids (wingspan 9–12 mm) and yellow dung flies (Scatophaga; wingspan 24 mm), but also of some larger insects such as dung beetles (Coleoptera; Scarabaeoidea), caddis-flies (Trichoptera) and moths (Lepidoptera). The echo target strength of some prey items was measured. Contrary to models based on standard targets such as spheres or disks, the echo strength of real insects was found to be virtually independent of the emitted frequency within the 20–100 kHz frequency range. A model was used to calculate probable detection distances of the prey by the bat. Using narrow-band calls of 13.7 ± 2.7 ms duration, a bat would detect the two smallest size classes of insect at greatest range using calls of 20 kHz. The results may therefore explain why many species of large and medium sized aerial-hawking bats use low-frequency calls and still eat mostly relatively small insects. The data and model challenges the assumption that small prey are unavailable to bats using low-frequency calls.     

Controlling industrial pollution using EIA: Case study of a Kenyan tannery project

Summary Since the late 1970s, the National Environment Secretariat (NES) in Kenya has viewed environmental impact assessment (EIA) as a principal tool for meeting its environmental protection objectives. Prior to the formation of the Inter-Ministerial Committee on the Environment (IMCE), NES was ineffective in forcing any project proponents to take the EIA requirements seriously. The IMCE has provided NES with the ability to co-opt Committee members and to use the legislatively based mandates of those members to enforce its EIA requirements for industrial projects. A successful example of this co-optation is the case of the Leather Industries of Kenya (LIK), involving a new tannery whose final siting and wastewater treatment control facilities were substantially influenced by the EIA process. Although the LIK case does not offer a basis for generalisation, it provides insights into: (a) how EIA is implemented for new industrial facilities in Kenya, (b) the advantages and disadvantages of the EIA system, and (c) the constructive roles donor agencies can play in promoting institutional reforms for EIA.Dr Rafik Hirji is a Senior Engineer at James M. Montgomery Consulting Engineers, Inc., Suite 160, Sacramento, CA 95825. He was formerly a graduate research assistant in the Department of Civil Engineering at Stanford University. Dr Leonard Ortolano is the UPS Foundation Professor of Civil Engineering at Stanford University, Stanford, CA 94305-4020, USA.     

A drowned Mesozoic bird breeding colony from the Late Cretaceous of Transylvania

Despite a rapidly improving fossil record, the reproductive biology of Mesozoic birds remains poorly known: only a handful of undisputed, isolated Cretaceous eggs (some containing embryonic remains) are known. We report here the first fossil evidence for a breeding colony of Mesozoic birds, preserved at the Late Cretaceous (Maastrichtian) Oarda de Jos (Od) site in the Sebe? area of Transylvania, Romania. A lens of calcareous mudstone with minimum dimensions of 80?cm length, 50?cm width and 20?cm depth contains thousands of tightly packed, morphologically homogenous eggshell fragments, seven near-complete eggs and neonatal and adult avialan skeletal elements. Eggshell forms 70–80?% of the matrix, and other fossils are entirely absent. The bones exhibit clear characters of the Cretaceous avialan clade Enantiornithes, and the eggshell morphology is also consistent with this identification. Both taphonomy and lithology show that the components of this lens were deposited in a single flood event, and we conclude that it represents the drowned remains of a larger enantiornithine breeding colony, swamped by rising water, washed a short distance and deposited in a shallow, low-energy pond. The same fate often befalls modern bird colonies. Such a large concentration of breeding birds suggests aquatic feeding in this species, augments our understanding of enantiornithine biology and shows that colonial nesting was not unique to crown birds.     

Role of amniotic fluid interphase fluorescence in situ hybridization (FISH) analysis in patient management

We retrospectively reviewed 309 amniotic fluid interphase fluorescence in situ hybridization (FISH) analyses performed from October 1995 to June 1999 to assess the role of interphase FISH in the management of patients at increased risk for fetal aneuploidies. Gestational age and indications for amniocentesis, clinical interventions after FISH results, as well as interventions after final culture reports were analyzed. There were 244 (79%) normal, 50 (16%) abnormal and 15 (5%) inconclusive FISH results. There were no false-positive or false-negative results, but there were nine (3%) clinically significant chromosomal abnormalities not detectable by FISH. Of the 50 women with abnormal FISH results, 26 (52%) elected to terminate the pregnancy prior to the availability of the standard chromosome analysis. In two of the fetuses with trisomy 21 no abnormalities were reported by ultrasound examination. Our experience indicates that interphase FISH results played an important role in decision making, especially for pregnancies close to 24 weeks' gestation. Standard karyotype analysis is still required for detection of chromosome abnormalities not detectable by interphase FISH techniques and for clarification of unusual or inconclusive FISH results. Copyright © 2001 John Wiley & Sons, Ltd.     

Sexual chases in sand martins (Riparia riparia): cues for males to increase their reproductive success

Summary During the pre-laying and laying stages of the breeding cycle, female sand martins are guarded by their mates and chased by other males seeking promiscuous copulations. Because females become exceptionally heavy when they are most likely to be fertile, their increased mass was thought to present cues during flight to males seeking promiscuous copulations. Heavy female sand martins released from the hand were selectively chased in sexual chases (Figs. 1, 2). Breeding females were heaviest during laying and pre-laying (Fig. 3), exceeding any masses normally achieved by breeding males (Fig. 3). A sample of naturally heavy females and birds whose mass had been experimentally increased to that of laying and prelaying females took longer to reach ascending flight, as determined by analysis of video recordings, than a sample of lighter birds (Table 1). It was concluded that this and other flight cues may be detected by males so that they may achieve extra-pair copulations and hence increase their reproductive success.