An assessment of microbial communities associated with surface mining-disturbed overburden

To assess the microbiological changes that occur during the maturation of overburden that has been disturbed by surface mining of coal, a surface mining-disturbed overburden unit in southeastern Ohio, USA was characterized. Overburden from the same unit that had been disturbed for 37 and 16 years were compared to undisturbed soil from the same region. Overburden and soil samples were collected as shallow subsurface cores from each subregion of the mined area (i.e., land 16 years and 37 years post-mining, and unmined land). Chemical and mineralogical characteristics of overburden samples were determined, as were microbial respiration rates. The composition of microbial communities associated with overburden and soil were determined using culture-independent, nucleic acid-based approaches. Chemical and mineralogical evaluation of overburden suggested that weathering of disturbed overburden gave rise to a setting with lower pH and more oxidized chemical constituents. Overburden-associated microbial biomass and respiration rates increased with time after overburden disturbance. Evaluation of 16S rRNA gene libraries that were produced by “next-generation” sequencing technology revealed that recently disturbed overburden contained an abundance of phylotypes attributable to sulfur-oxidizing Limnobacter spp., but with increasing time post-disturbance, overburden-associated microbial communities developed a structure similar to that of undisturbed soil, but retained characteristics of more recently disturbed overburden. Our results indicate that over time, the biogeochemical weathering of disturbed overburden leads to the development of geochemical conditions and microbial communities that approximate those of undisturbed soil, but that this transition is incomplete after 37 years of overburden maturation.     

Kinetics and reversibility of micropollutant sorption in sludge

The fate of micropollutants throughout wastewater treatment systems is highly dependent on their sorption interactions with sludge matter. In this study, both the sorption and desorption kinetics of polycyclic aromatic hydrocarbons (PAHs) in activated sludge were shown to be very rapid in comparison to biodegradation kinetics. It was concluded that PAH transfer does not limit their biodegradation and that their fate is governed by the sorption/desorption equilibrium state. The effect of contact time between sludge and PAHs was also investigated. It was shown that aging did not influence the sorption/desorption equilibrium although PAH losses during aging suggest that sequestration phenomena had occurred. This implies that for PAH sorption assessment within treatment processes there is no need to include a contact time dimension. As a consequence, thanks to an innovative approach taking into account sorption equilibria and sequestration, this work has demonstrated that studies in the literature which, in main, deal with micropollutant sorption in sewage sludge with only a short contact time can be extrapolated to real systems in which sorption, desorption and aging occur.     

Campomelic acampomelic dysplasia presenting with increased nuchal translucency in the first trimester

This is the first report of a fetus affected with campomelic acampomelic dysplasia presenting with increased nuchal translucency. Ultrasonography at 13 weeks of amenorrhea showed a nuchal translucency 5.6 mm thick. The karyotype performed on amniotic fluid cells was normal (46,XY). Ultrasonography at 22 weeks revealed a normal femoral length and female genitalia. A second amniocentesis was performed to confirm the karyotype and for dosage of steroid hormones. Testosterone dosage was low, corresponding to a female fetus. Ultrasonography at 32 weeks showed growth retardation of the long bones (<3rd centile) that were not curved. A severe malformation syndrome was suspected and the pregnancy was terminated at 33 weeks. The fetus displayed macrocephaly, facial dysmorphism and female external genitalia. X ray showed straight and thickened long bones, hypoplastic scapulae and moderate platyspondyly. In view of the association of sex reversal, hypoplasia of the scapulae, and the presence of straight long bones, campomelic acampomelic dysplasia was suspected and confirmed by the finding of a SOX9 mutation. This case shows the importance of a careful echographic survey in a fetus with a nuchal translucency > 4 mm, especially if there is discordance between phenotypic and genotypic sex, since growth retardation may occur later during the pregnancy. Copyright © 2004 John Wiley & Sons, Ltd.     

Improvement of mesenteric superior artery Doppler velocimetry by amnio-infusion in fetal gastroschisis†

This study aimed to analyse the influence of amnio-infusion on superior mesenteric Doppler velocimetry and to correlate Doppler data with outcome in fetuses presenting with gastroschisis. Umbilical and intra- and extra-abdominal superior mesenteric artery Doppler velocimetry was measured prospectively before and after amnio-infusion in fetuses with gastroschisis. Doppler index values and changes were correlated with the following outcome parameters: importance of fibrous coating, duration of hospitalization in the neonatal intensive care unit, total duration of hospitalization, duration of parenteral feeding, duration of ventilatory assistance, and the interval to initiation of oral feeding. A significant improvement of diastolic flow was observed in the extra-abdominal superior mesenteric artery with amnio-infusion. No similar change was seen in the intra-abdominal superior mesenteric or in the umbilical artery. Pre-amnioinfusion extra-abdominal mesenteric Doppler index was correlated with maximal diameter of exteriorized bowel and slightly with duration of hospitalization in the neonatal intensive care unit, but no other relation between Doppler index and outcome parameter could be ascertained. Amnio-infusion induces modifications in the vascularization of exteriorized bowel in gastroschisis. This could partly explain the beneficial effect of this procedure on fetal gut. Copyright © 2001 John Wiley & Sons, Ltd.     

Characterisation, dissemination and persistence of gentamicin resistant Escherichia coli from a Danish university hospital to the waste water environment

The aim of the study was to investigate the potential spread of gentamicin resistant (GEN(R)) Escherichia coli isolates or GEN(R) determinants from a Danish university hospital to the waste water environment. Waste water samples were collected monthly from the outlets of the hospital bed wards and the inlet of the related waste water treatment plant (WWTP) from October 2002 to August 2003. Waste water samples were also collected monthly from a residential area in the same period to be able to compare the prevalence of GEN(R)E. coli isolates from hospital related and residential waste water. The waste water isolates were compared to GEN(R)E. coli isolates obtained consecutively from September 2002 to September 2003 from patients mainly with urinary tract infections at the hospital with respect to Pulsed Field Gel Electrophoresis (PFGE) profiles. All isolates were investigated for GEN(R) mechanisms (aac(3)-II, aac(3)-IV, ant(2')-I, armA), phenotypic resistance pattern, and virulence genes (hlyA, chuA, sfaS, fogG, malX, traT, iutA, fyuA, iroN, cnf1) to investigate if the hospital and waste water could be reservoirs of antimicrobial resistance and virulence. The ability for GEN(R) determinants to transfer horizontally was investigated by mating experiments. A total of 38, 15, 21, and two GEN(R)E. coli were isolated from patients, the hospital outlets, the inlet of the WWTP, and the residential area, respectively. GEN(R)E. coli were more prevalent in waste water from the hospital and the WWTP than in waste water from the residential area. PFGE profiling revealed no spread of specific patient isolates to the waste water. The aac(3)-II gene was detected both in patient and waste water isolates. Furthermore horizontal transfer of the aac(3)-II gene of patient origin to a recipient was shown in vitro, indicating a potential spread of the gene from patient isolates to waste water isolates. Regardless of origin, most isolates exhibited multi-resistance and contained several virulence genes. In conclusion, our study showed a possible spread of aac(3)-II from the hospital to the waste water. Most of the GEN(R)E. coli isolates from both patients and waste water had a multi-resistant phenotype and contained virulence genes and should therefore be considered reservoirs of antimicrobial resistance and virulence genes.     

Postmating changes in cuticular chemistry and visual appearance in <Emphasis Type="Italic">Ectatomma tuberculatum</Emphasis> queens (Formicidae: Ectatomminae)

In the ectatommine ant Ectatomma tuberculatum, the visual appearance of queens changes after mating and ovarian development in that their cuticle turns from shiny to matte. In this study, we have shown that this change seems to be caused by 15-fold accumulation of hydrocarbons, in particular heptacosane that covers the multiple grooves present on the cuticular surface creating a wax coat in mated fully fertile queens. Analyses of the scrapped wax revealed that it is composed largely of heptacosane. Peak-by-peak comparison of the cuticular hydrocarbon (CHC) composition of mated, virgin with developed ovaries and virgin with nondeveloped ovaries revealed significant differences between the queen groups. Although the total amount of the CHC of virgin queens with developed ovaries was not higher than virgin queens that did not have developed ovaries, the composition showed a shift toward the mated queen. While it is possible that the large accumulation of hydrocarbons may give extra physical and chemical protection to queens, we propose that the switch in the relative abundance of heptacosane and nonacosane and perhaps of other components is indicative of being a mating and fertility cue. This is the first report in social insects where external chemical changes are accompanied by changes in visual appearance.     

Suicidal behavior by motor vehicle collision

BACKGROUND: The ability for suicides of drivers to be disguised as traffic accidents raises the possibility that suicidal behaviors of this nature are far more prevalent than previously thought, potentially impacting health, road safety, and insurance companies. METHOD: Persons residing at the Gold Coast, Australia, identified as having a history of suicidal ideation and behaviors (n = 1,196), were sent a mail-out survey after their consent was obtained in initial telephone contact (CATI random digit-dialing). Among those responding, 412 had made suicide plans or arrangements and 228 suicide attempts. RESULTS: Of those who reported planning a suicide, 14.8% (19.1% of male planners and 11.8% of female planners) had conceived to have a motor vehicle "accident" (n = 61). Of all attempters, 8.3% (13.3% of male attempters) had previously attempted via motor vehicle collision (n = 19). All attempters reported having emotional or mental problems at the time of the event. Suicide planners were significantly more likely to be in full-time employment and have a partner and children compared with other planners. CONCLUSION: The study gives a rare insight into driver suicide plans and attempts, via a large-scale community survey, to provide the best opportunity of collecting unbiased data on the driver suicide behavior. Results suggest the use of this method, particularly in attempts made by males, may be underreported leading to inaccuracy of statistics. The motives behind choosing this method are somewhat different to those behind other methods, including financial benefits and eliminating stigma in the aftermath of a suicide.     

Insecticide resistance may enhance the response to a host-plant volatile kairomone for the codling moth, <Emphasis Type="Italic">Cydia pomonella</Emphasis> (L.)

The behavioral and electroantennographic responses of Cydia pomonella (L.) to the ripe pear volatile ethyl (2E,4Z)-2,4-decadienoate (Et-E,Z-DD), were compared in insecticide-susceptible and -resistant populations originating from southern France. A dose–response relationship to this kairomonal attractant was established for antennal activity and did not reveal differences between susceptible and resistant strains. Conversely, males of the laboratory strains expressing metabolic [cytochrome P450-dependent mixed-function oxidases (mfo)] or physiological (kdr-type mutation of the sodium-channel gene) resistance mechanisms exhibited a significantly higher response to Et-E,Z-DD than those of the susceptible strain in a wind tunnel experiment. No response of the females to this kairomone could be obtained in our wind-tunnel conditions. In apple orchards, mfo-resistant male moths were captured at significantly higher rates in kairomone-baited traps than in traps baited with the sex pheromone of C. pomonella. Such a differential phenomenon was not verified for the kdr-resistant insects, which exhibited a similar response to both the sex pheromone and the kairomonal attractant in apple orchards. Considering the widespread distribution of metabolic resistance in European populations of C. pomonella and the enhanced behavioral response to Et-E,Z-DD in resistant moths, the development of control measures based on this kairomonal compound would be of great interest for the management of insecticide resistance in this species.     

A novel approach to the sequential extraction of plutonium from oxic and anoxic sediment using sodium citrate to inhibit post-extraction resorption

Sequential extraction has been used extensively to study the solid partitioning of radionuclides in soils and sediments. A difficulty with sequential extraction is that radionuclides released by a particular extractant can be resorbed and artificially redistributed amongst the remaining solid phases. Here, we describe experiments (on selected model phase and natural materials), which were designed to determine whether the inclusion of a chelating agent (sodium citrate) in an established sequential extraction protocol (a) inhibits post-extraction resorption of plutonium, (b) increases non-targeted dissolution of sediment phases, and (c) gives rise to unwanted ligand competition for plutonium. The results clearly demonstrate the capacity of citrate to inhibit the resorption of plutonium from the various extractants, and confirm that there is no discernible increase in non-targeted phase dissolution, but indicate significant ligand competition with the carbonate phase. The merits of using citrate are discussed and an optimised sequential extraction protocol that includes citrate is proposed. Finally, the protocol is applied to oxic and anoxic sediments sampled in the NE Irish Sea and the Roads of Cherbourg, and it is shown that the bulk of the plutonium on these sediments is associated with the more labile geochemical fractions.