Persistent effects of underground longwall coal mining on freshwater wetland hydrology

More than half of global wetlands have been lost because of anthropogenic disturbance, with the trend of decline continuing in the 21st century. While much of this loss relates to changes in surface flows, groundwater is also critical to sustaining wetland hydrology. Underground longwall mines extract coal seams, in turn fracturing the overlying stratigraphy, influencing aquifer connectivity and affecting surface flows via subsidence disturbance. Crucially, this subterranean disturbance may disrupt the hydrological processes that sustain freshwater wetlands at the surface. Here we present a new designed empirical study that compares the persistence of soil moisture after a rainfall event in wetlands subject to underground longwall coal mining to that in unmined reference wetlands. Accelerated Failure Time models showed that mined wetlands were persistently drier, retained water for shorter durations and exhibited less spatial differentiation than unmined wetlands. This quantitative evidence of severe, persistent hydrological change following resource extraction reinforces earlier observations and has important implications for biodiversity and provision of ecosystem services to a large urban population. If Ecologically Sustainable Development (ESD) outcomes and effective deployment of the mitigation hierarchy are to be achieved in line with current legislative and policy paradigms, our results highlight the need for more emphasis on impact avoidance and minimisation than restoration or offsetting to protect water and biodiversity values. Given severe constraints on restoration success, greater emphasis on avoidance in mine design and approval processes offers realistic opportunities for an improved balance between sustaining irreplaceable public assets and short-term benefits from non-renewable resource extraction.

Duration of the preejection phase is less preload dependent and therefore a better marker of acute response to cardiac resynchronization therapy than maximum pressure rise

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): EU’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie

Background

There is no consensus on which haemodynamic marker should be used to quantify acute response to cardiac resynchronization therapy (CRT) during implantation of the device. CRT has been shown to acutely reduce left ventricular (LV) end systolic as well as end-diastolic volume (EDV), precluding the use of preload dependent markers such as LV maximum pressure rise (dP/dtmax).

Purpose

As resynchronization will abolish the uncoordinated regional early systolic contractions of the LV, it will shorten the time to maximal pressure rise and aortic valve opening. For this reason, the purpose of this study was to investigate if duration from the time-point of ventricular pacing to dP/dtmax is less preload dependent and a better marker of acute response to CRT than dP/dtmax by comparing how the 2 markers reflected LV function during different CRT configurations.

Methods

LV pressure by micromanometer and volume by sonomicrometry were measured in 6 anaesthetized canines with left bundle branch block. Transient caval constrictions were performed to vary preload. Preload dependency of the 2 markers was compared by normalizing their values and calculating their relations to EDV. In 4 of the animals, biventricular pacing was performed at 3 different pacing sites with variations in atrioventricular delays that provided a range of response to CRT. To correct for acute

changes in preload by CRT, stroke volume (SV) at identical EDV found from transient caval constrictions, were assessed and used as reference to grade improved LV function. Linear regression analysis was used to assess the correlation of both the duration of the preejection phase and dP/dtmax with SV.

Results

The duration of the preejection phase varied less with changes in preload compared to dP/dtmax: the slopes of their relation to EDV were -0.6 ± 0.7 %/ml and 4.8 ± 2.1 %/ml (p = 0.004), respectively. Turning CRT on, acutely reduced EDV from 74 ± 16 to 69 ± 17 ml (p < 0.001) at the best pacing configuration. For the different pacing sites and settings, there was a consistent relation in all animals where the preejection phase shortened as SV increased (average r2 = 0.75) (Figure A). dP/dtmax showed no clear relation to SV (average r2 = 0.22) and included cases with both negative and positive slopes (Figure B).

Conclusions

The duration of the preejection phase correlated with changes in LV function induced by CRT while dP/dtmax performed poorly as preload was changed. Hence, the novel timing parameter was less preload dependent and may be a better marker for assessing acute response to CRT. Abstract Figure.

Soil inactivation of DNA viruses in septic seepage

AIMS

To generate field-relevant inactivation data for incorporation into models to predict the likelihood of viral contamination of surface waters by septic seepage.

METHODS AND RESULTS

Inactivation rates were determined for PRD1 bacteriophage and Adenovirus 2 in two catchment soils under a range of temperature, moisture and biotic status regimes. Inactivation rates presented for both viruses were significantly different at different temperatures and in different soil types (alpha = 0.05). Soil moisture generally did not significantly affect virus inactivation rate. Biotic status significantly affected inactivation rates of PRD1 in the loam soil but not the clay-loam soil. Adenovirus 2 was inactivated more rapidly in the loam soil than PRD1 bacteriophage.

CONCLUSIONS

Virus inactivation rates incorporated into models should be appropriate for the climate/catchment in question with particular regard to soil type and temperature. Given that PRD1 is similar in size to adenoviruses, yet more conservative with regard to inactivation in soil, it may be a useful surrogate in studies of Adenovirus fate and transport.

SIGNIFICANCE AND IMPACT OF THE STUDY

A better understanding of the factors that govern virus fate and transport in catchments would facilitate the design of barrier measures to prevent viral contamination of surface waters by septic seepage.

Environmental inactivation of Cryptosporidium oocysts in catchment soils

AIMS

To generate field-relevant inactivation rates for Cryptosporidium oocysts in soil that may serve as parameter values in models to predict the terrestrial fate and transport of oocysts in catchments.

METHODS AND RESULTS

The inactivation of Cryptosporidium oocysts in closed soil microcosms over time was monitored using fluorescence in situ hybridization (FISH) as an estimate of oocyst 'viability'. Inactivation rates for Cryptosporidium in two soils were determined under a range of temperature, moisture and biotic status regimes. Temperature and soil type emerged as significantly influential factors (P < 0.05) for Cryptosporidium inactivation. In particular, temperatures as high as 35 degrees C may result in enhanced inactivation.

CONCLUSIONS

When modelling the fate of Cryptosporidium oocysts in catchment soils, the use of inactivation rates that are appropriate for the specific catchment climate and soil types is essential. FISH was considered cost-effective and appropriate for determining oocyst inactivation rates in soil.

SIGNIFICANCE AND IMPACT OF THE STUDY

Previous models for predicting the fate of pathogens in catchments have either made nonvalidated assumptions regarding inactivation of Cryptosporidium in the terrestrial environment or have not considered it at all. Field-relevant inactivation data are presented, with significant implications for the management of catchments in warm temperate and tropical environments.

Mitochondrial DNA signatures of restricted gene flow within divergent lineages of an atyid shrimp (Paratya australiensis)

We measured spatial genetic structure within three previously described mitochondrial lineages of the atyid shrimp, Paratya australiensis, occurring in upland streams of two major catchments within the Sydney Water Supply Catchment, New South Wales, Australia. In all three lineages, there was significant spatial structuring of genetic variation between catchments. In two lineages, recurrent but restricted maternal gene flow has apparently predominated in shaping within-catchment genetic structure, although this framework may be overlaid with episodic contiguous/long-distance expansion events. In the third lineage, there was no evidence of spatial genetic structuring within one of the catchments, because one haplotype was both common and widespread throughout the sampled area. High-frequency haplotypes were also shared among subcatchments in the other two lineages, and we discuss both historical and contemporary processes that may have left these genetic signatures. Our results are generally concordant with previous reports of significant population structuring in P. australiensis, occurring in upland river reaches elsewhere in eastern Australia. We propose that restricted dispersal and gene flow among upland populations of P. australiensis is linked to dramatic architectural structuring within and among mountain streams.

Liquid-phase microextraction as a sample preparation technique prior to capillary gas chromatographic-determination of benzodiazepines in biological matrices

Liquid-phase microextraction (LPME) and gas chromatography were applied to determine diazepam and the main metabolite N-desmethyldiazepam in human urine and plasma. The analytes were extracted from 3.0-3.5 ml sample volumes directly into 25 microl of extraction solvent. The microextraction device consisted of a porous hollow fiber of polypropylene attached to two guiding needles inserted through a septum and a 4 ml vial. The hollow fiber filled with extraction solvent was immersed in sample solution. The extraction device was continuously vibrated at 600 rpm for 50 min. An aliquot (1 microl) of the extraction solvent with preconcentrated analytes was injected directly into the capillary gas chromatograph. Thirty samples were extracted simultaneously on the vibrator, providing a high sample capacity. The limits of detection were from 0.020 to 0.115 nmol/ml for diazepam and N-desmethyldiazepam in plasma and urine using a nitrogen-phosphorus detector (NPD).

Development of a simple in-vial liquid-phase microextraction device for drug analysis compatible with capillary gas chromatography, capillary electrophoresis and high-performance liquid chromatography

A simple, inexpensive and disposable device for liquid-phase microextraction (LPME) is presented for use in combination with capillary gas chromatography (GC), capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC). 1-4 ml samples of human urine or plasma were filled into conventional 4-ml vials, whereafter 15-25 microl of the extraction medium (acceptor solution) was filled into a short piece of a porous hollow fiber and placed into the sample vial. The drugs of interest were extracted from the sample solutions and into the small volumes of acceptor solution based on high partition coefficients and were preconcentrated by a factor of 30-125. For LPME in combination with GC, the porous hollow fiber was filled with 15 microl n-octanol as the acceptor solution. Following 30 min of extraction, the organic acceptor solution was injected directly into the GC system. For LPME in combination with CE and HPLC, n-octanol was immobilized within the pores of the hollow fiber, while the internal volume of the fiber was filled with either 25 microl of 0.1 M HCl (for extraction of basic compounds) or 25 microl 0.02 M NaOH (for acidic compounds). Following 45 min extraction, the aqueous acceptor solution was injected directly into the CE or HPLC system. Owing to the low cost, the extraction devices were disposed after a single extraction which eliminated the possibility of carry over effects. In addition, because no expensive instrumentation was required for LPME, 10-30 samples were extracted in parallel to provide a high number of samples per unit time capacity.

Automated determination of 'Ecstasy' and amphetamines in urine by SPME and capillary gas chromatography after propylchloroformate derivatisation

The determination of amphetamines and their methylenedioxylated analogs in urine by propylchloroformate derivatisation and automated solid-phase microextraction is described. The urine sample was adjusted to pH 10.8 and added propylchloroformate reagent and an internal standard. Derivatisation resulted in water-stable carbamates which were automatically extracted by solid-phase microextraction. A fiber coated with polydimethylsiloxane was inserted into the urine matrix and agitated for 16 min. The fibre with the extracted carbamates was injected into the heated split-splitless injection port of the gas chromatograph where the analytes were evaporated at 300 degrees C, separated on a methylsilicone capillary column and detected by either a nitrogen phosphorous detector or by mass spectrometry. The method was shown to be highly reproducible and robust with respect to variations in the urine matrices. The detection limits were 5 ng/ml(-1) of methamphetamine, MDMA and MDEA and 15 ng/ml(-1) of amphetamine and MDA in urine. The method is a solvent free, automated alternative to traditional methods for determination of the amphetamine and their methylendioxylated analogs in urine.

Aqueous alkylchloroformate derivatisation and solid-phase microextraction: determination of amphetamines in urine by capillary gas chromatography

The alkylchloroformate derivatisation and solid-phase microextraction of amphetamine and methamphetamine directly in urine samples prior to capillary gas chromatographic analysis is described. The alkylchloroformate reagent was added to the urine sample, which was adjusted to pH 10.8, and an internal standard was added. The resulting products were water-stable carbamates that were extracted without organic solvent. The polydimethylsiloxane coated fibre was inserted into the modified sample and agitated for 14 min. The fibre with the extracted derivatisation products was injected into the capillary gas chromatograph. The extracted carbamates were evaporated at 300 degrees C in the split-splitless injection port of the gas chromatograph, separated on a methylsilicone capillary column and detected by either a nitrogen-phosphorus detector or by mass spectrometry. The method was shown to be reproducible with a detection limit of 50 ng/ml of amphetamine and methamphetamine in urine.

Automated on-line dialysis, trace enrichment and high-performance liquid chromatography. Inhibition of interaction with the dialysis membrane and disruption of protein binding in the determination of clozapine in human plasma

Problems related to interaction of drugs with the dialysis membrane and to protein binding must be overcome in order to develop automated methods for drug analysis based on on-line dialysis, trace enrichment and HPLC. In order to study these problems, clozapine and its active metabolite N-desmethylclozapine were chosen as model compounds because they were found to interact with the dialysis membrane, and clozapine is highly protein bound. Addition of a cationic surfactant, dodecylethyldimethyl ammonium bromide, to the donor solution and to the plasma samples was found to inhibit interaction of the drugs with surfaces. The protein binding in plasma was disrupted prior to dialysis by lowering the pH with hydrochloric acid and the plasma proteins were solubilised with glycerol. The results obtained were used to develop a fully automated method for the determination of clozapine and N-desmethylclozapine in human plasma. More than 100 samples could be analysed within 24 h. The limit of detection in human plasma was 0.050 mumol/l for clozapine and 0.055 mumol/l for N-desmethylclozapine. Linearity was found for drug concentrations between 0.25-3 mumol/l. The relative standard deviations were between 1.2-6.7% and the method was applicable for therapeutic drug monitoring.

Solvent-modified solid-phase microextraction for the determination of diazepam in human plasma samples by capillary gas chromatography

This paper describes microextraction and gas chromatographic analysis of diazepam from human plasma. The method was based on immobilisation of 1.5 microliters of 1-octanol on a polyacrylate-coated fiber designed for solid-phase microextraction. The solvent-modified fibre was used to extract diazepam from the samples. The plasma sample was pre-treated to release diazepam from the protein binding. The fibre was inserted into the modified plasma sample, adjusted to pH 5.5 an internal standard was added and the mixture was carefully stirred for 4 min. The fibre with the immobilised solvent and the enriched analytes was injected into the capillary gas chromatograph. The solvent and the extracted analytes were evaporated at 300 degrees C in the split-splitless injection port of the gas chromatograph, separated on a methylsilicon capillary column and detected with a nitrogen-phosphorus detector. The method was shown to be reproducible with a detection limit of 0.10 nmol/ml in human plasma.

Solid-phase microextraction for the determination of the free concentration of valproic acid in human plasma by capillary gas chromatography

The potential of solid-phase microextraction in the bioanalysis of drugs is demonstrated. The free concentration of valproic acid in human plasma was determined by equilibrium dialysis at room temperature. To the dialysate was added an internal standard and the pH was adjusted to 2.5. The polymethylsiloxane-coated fused-silica fibre of the solid-phase microextraction device was inserted into the dialysate for 3 min. The sorbed analytes were then thermally desorbed at 210 degrees C in the split-splitless injection port of the gas chromatograph, separated on a Nukol capillary column and detected with a flame ionization detector. The method was shown to be highly reproducible with a detection limit of 1 microgram/ml of free valproic acid in human plasma.

Automated analysis of free and total concentrations of three antiepileptic drugs in plasma with on-line dialysis and high-performance liquid chromatography

A fully automated method for determination of the free and total concentration of drugs with a varying degree of protein binding is described. The antiepileptic drugs phenytoin, carbamazepine and phenobarbitone were chosen to demonstrate the utility of this technique. The method was based on the ASTED system and combined on-line equilibrium dialysis at 37 degrees C with concentration of the dialysate on a trace enrichment column and HPLC determination with UV detection. The dialysis cell was a modification of the ASTED dialysis cell and 22% of the free concentration of the drugs were recovered in the recipient channel of the dialyser after 10 min of dialysis at 37 degrees C. The free concentration, the total concentration as well as the drugs protein binding could be determined. The method was shown to be well suited for routine monitoring of the free and the total concentrations of the drugs in plasma from epileptic patients.

Automated sample preparation by on-line dialysis and trace enrichment. Analysis of morphine, 6-monoacetylmorphine, codeine, ethylmorphine and pholcodine in plasma and whole blood by capillary gas chromatography and capillary gas chromatography-mass spectrometry

A fully automated sample preparation method for the determination of five opiates in human plasma and whole blood is described. The technique combines dialysis and trace enrichment prior to gas chromatography and gas chromatography-mass spectrometry. Dialysis and trace enrichment on a polymer column was shown to be a highly reliable method for sample preparation. The method can be used, after minor modification, to determine other basic drugs in plasma and whole blood. The method demonstrates the potential of the automated sequential trace enrichment of dialysate (ASTED) system for automated sample preparation.

[Young persons sentenced to psychiatric treatment in Copenhagen]

The material consisted of 87 persons given a sentence in the years 1978 to 1987. Twenty-seven were under 23 years. There was no significant difference in the number of persons sentenced each year in the ten year period. The age of the patients was between 16 and 29 years with the median age being nearly 25 years. Most of the patients had a psychosis. The youngest group (less than 23 years) had a greater proportion of non-psychotic illness. Most of the patients were males. They had committed serious crimes and were sentenced to treatment in psychiatric hospitals with contact to a probation officer during out-patient treatment. Most of the patients were treated with neuroleptics, whereas psychotherapy, education and work-training were rare. The ability to attend out-patient treatment was generally low, and most of the patients were taken in for hospital treatment, according to the requirements of the sentence, because they did not keep their appointments. In order to increase the quality of the treatment offered it is recommended that special forensic psychiatric departments are established. This has taken place in the Copenhagen mental health hospital in 1989.

On-line dialysis and weak cation-exchange enrichment of dialysate. Automated high-performance liquid chromatography of pholcodine in human plasma and whole blood

An automated method for the determination of pholcodine in plasma and whole blood is described. The technique combines dialysis and trace enrichment prior to high-performance liquid chromatography. Dialysis, trace enrichment on a weak cation-exchange column, separation on a cyano column and fluorescence detection was shown to be an extremely selective and sensitive method. The method has been used successfully in the analysis of real samples after administration of pholcodine. The automated method can be used, after minor modification, to determine other basic drugs in whole blood and plasma.

Notes on the distribution, abundance, diet and habitat of the New Guinea murid (Rodentia) Xenuromys barbatus (Milne-Edwards, 1900)

NA