Quantifying Outdoor Water Consumption of Urban Land Use/Land Cover: Sensitivity to Drought

Outdoor water use is a key component in arid city water systems for achieving sustainable water use and ensuring water security. Using evapotranspiration (ET) calculations as a proxy for outdoor water consumption, the objectives of this research are to quantify outdoor water consumption of different land use and land cover types, and compare the spatio-temporal variation in water consumption between drought and wet years. An energy balance model was applied to Landsat 5 TM time series images to estimate daily and seasonal ET for the Central Arizona Phoenix Long-Term Ecological Research region (CAP-LTER). Modeled ET estimations were correlated with water use data in 49 parks within CAP-LTER and showed good agreement (r ² = 0.77), indicating model effectiveness to capture the variations across park water consumption. Seasonally, active agriculture shows high ET (>500 mm) for both wet and dry conditions, while the desert and urban land cover types experienced lower ET during drought (<300 mm). Within urban locales of CAP-LTER, xeric neighborhoods show significant differences from year to year, while mesic neighborhoods retain their ET values (400–500 mm) during drought, implying considerable use of irrigation to sustain their greenness. Considering the potentially limiting water availability of this region in the future due to large population increases and the threat of a warming and drying climate, maintaining large water-consuming, irrigated landscapes challenges sustainable practices of water conservation and the need to provide amenities of this desert area for enhancing quality of life.     

Toxicity of emerging energetic soil contaminant CL-20 to potworm Enchytraeus crypticus in freshly amended or weathered and aged treatments

We investigated the toxicity of an emerging polynitramine energetic material hexanitrohexaazaisowurtzitane (CL-20) to the soil invertebrate species Enchytraeus crypticus by adapting then using the Enchytraeid Reproduction Test (ISO/16387:2003). Studies were designed to develop ecotoxicological benchmark values for ecological risk assessment of the potential impacts of accidental release of this compound into the environment. Tests were conducted in Sassafras Sandy Loam soil, which supports relatively high bioavailability of CL-20. Weathering and aging procedures for CL-20 amended into test soil were incorporated into the study design to produce toxicity data that better reflect soil exposure conditions in the field compared with the toxicity in freshly amended soils. Concentration-response relationships for measurement endpoints were determined using nonlinear regressions. Definitive tests showed that toxicities for E. crypticus adult survival and juvenile production were significantly increased in weathered and aged soil treatments compared with toxicity in freshly amended soil, based on 95% confidence intervals. The median effect concentration (EC50) and EC20 values for juvenile production were 0.3 and 0.1 mg kg-1, respectively, for CL-20 freshly amended into soil, and 0.1 and 0.035 mg kg-1, respectively, for weathered and aged CL-20 soil treatments. These findings of increased toxicity to E. crypticus in weathered and aged CL-20 soil treatments compared with exposures in freshly amended soils show that future investigations should include a weathering and aging component to generate toxicity data that provide more complete information on ecotoxicological effects of emerging energetic contaminants in soil.     

Identifying source correlation parameters for hydrocarbon wastes using compound-specific isotope analysis

A preliminary evaluation of compound-specific isotope analysis (CSIA) as a novel, alternative method for identifying source correlation compounds in soils contaminated with residual heavy or weathered petroleum wastes is presented. Oil-contaminated soil microcosms were established using soil (sandy-loam, non-carbonaceous cley) amended with ballast-, crude- or No.6 fuel oil. Microcosms were periodically sampled over 256 days and delta(13)C values (which express the ratio of (13)C to (12)C) determined at each time point for five n-alkanes and the isoprenoid norpristane using gas chromatography-isotope ratio mass spectrometry (GC-IRMS). Although some temporal variation was observed, no significant temporal shifts in the delta(13)C values for the five n-alkanes were measured in all three oils. Isoprenoid isotope ratios (delta(13)C) appeared to be least affected by biotransformation, especially in the No.6 fuel oil. The research suggests that the delta(13)C of isoprenoids such as norpristane, may be of use as source correlation parameters.     

An Investigation Into the Mechanism by Which Synthetic Zeolites Reduce Labile Metal Concentrations in Soils

The addition of synthetic zeolites and similar materials to metal contaminated soils has been shown to reduce soil phytotoxicity and to improve the quality of plant growth on such amended soils. To gain an understanding of the mechanism by which the phytotoxicity of contaminated soils is reduced when treated with synthetic zeolites, sequential extraction procedures and soil solution techniques have been used to identify changes associated with metal speciation in amended soils. Sequential extraction data and changes in soil solution composition are presented for three different contaminated soils, amended with three synthetic zeolites (P, 4A and Y) at concentrations of 0.5%, 1% and 5% w/w, or lime at 1%. The soils were collected from the site of a metal refinery, an old lead zinc mine spoil tip and from a field which had been treated with sewage sludge. After incubation of the zeolite treated soils for between one and three months, results showed a reduction in the metal content of the ammonium acetate fraction between 42% and 70%, depending on soil, zeolite and rate of addition, compared with the unamended soils. In addition, soil solution experiments indicated that synthetic zeolite amendments were more efficient at reducing metal content than comparable lime treatment. The mechanism by which synthetic zeolites reduce metal bioavailability in contaminated soils is discussed and compared to other amendments.     

Improving mental health status and coping abilities for long‐term unemployed youth using cognitive‐behaviour therapy based training interventions

This paper reports on immediate and long‐term well‐being outcomes for a group of long‐term unemployed youth who attended specially devised training courses based on the cognitive‐behaviour therapy (CBT) model. The courses were aimed specifically at improving the mental health of participants, and providing them with coping skills to deal better with the negative consequences of prolonged unemployment. Results for participants were compared with a waiting‐list, control group. Outcomes investigated were well‐being (psychological distress, self‐esteem, positive and negative affect), and coping behaviours (social support, self care, recreation, and cognitive coping strategies). Behavioural plasticity effects were also examined by comparing outcomes for participants who had higher distress scores prior to the course with participants who reported lower scores at that time. Immediate benefits were identified for both mental health and coping behaviours, and many of these benefits persisted into the long term. Participants with higher levels of pre‐course psychological distress improved more than their low distressed counterparts, supporting the behavioural plasticity hypothesis. Copyright © 1999 John Wiley & Sons, Ltd.     

Solomon versus selective fetoscopic laser photocoagulation for twin-twin transfusion syndrome: A systematic review and meta-analysis

This meta-analysis aims to compare the perinatal outcome of twin-twin transfusion syndrome (TTTS) pregnancies undergoing selective versus vascular equator (Solomon) fetoscopic laser photocoagulation (FLP). We performed a systematic search in PubMed and Web of Science from inception up to 25 July 2021. Studies comparing the Solomon and selective techniques of FLP for treatment of TTTS pregnancies were eligible. Random-effects or fixed-effect models were used to pool standardized mean differences (SMD) and log odds ratio. Seven studies with a total of 1664 TTTS pregnancies (n = 671 undergoing Solomon and n = 993 selective techniques) were included. As compared to the selective FLP, Solomon was associated with a lower risk of recurrent TTTS compared to the selective technique (Log odds ratio [OR]: −1.167; 95% credible interval [CrI]: −2.01, −0.33; p = 0.021; I²: 67%). In addition, Solomon was significantly associated with a higher risk of placental abruption than the selective technique (Log [OR]: 1.44; 95% CrI: 0.45, 2.47; p = 0.012; I²: 0.0%). Furthermore, a trend for the higher risk of preterm premature rupture of membranes was observed among those undergoing Solomon (Log [OR]: 0.581; 95% CrI: −0.43, 1.49; p = 0.131; I²: 17%). As compared to selective FLP, the Solomon technique for TTTS pregnancies is associated with a significantly lower recurrence of TTTS; however, it significantly increases the risk of placental abruption.     

Design of Polyhydroxyalkanoate (PHA) Microbeads with Tunable Functional Properties and High Biodegradability in Seawater

Journal of Polymers and the Environment - Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) were used to prepare microbeads, with diameter ranging from...