Inorganic phosphorous availability and mobility in a manufactured soil.

Manufactured soils, created by combining various organic and inorganic waste materials and byproducts, may be tailored to specific applications, providing an alternative to the extraction of natural soils. It is important for them to be capable of supporting plant growth without the need for significant management or fertiliser applications, the over-application of which can have adverse environmental effects. We examined the dynamics of phosphorus (P) transformations within a manufactured soil and the implications for nutrient cycling. A freshly prepared manufactured soil (32.5 % composted green waste, 32.5 % composted bark, 25 % horticultural grit, and 10 % lignite clay) was studied over one year in temperature and moisture controlled mesocosms. Leachate was collected to achieve high-resolution monitoring of leached phosphate concentrations. Initially, leached dissolved inorganic phosphorus (DIP) concentrations were low (0.02 ± 0.01 mg P L-1), before increasing by 160 µg P L-1 d-1 over the first 42 days to 5.57 ± 1.23 mg P L-1. After reaching a maximum concentration, DIP concentrations remained relatively consistent, varying by only 1.67 mg P L-1 until day 270. The increase in leached DIP was likely driven by soil organic matter mineralisation and the cleavage of carbon­phosphorus bonds by the soil microbes to satisfy carbon demand with mineralogical influences, such as a decrease in apatite content, also contributing. Sorption and desorption from soil particles were the processes behind the P loss from the soil, which was followed by slow diffusion and eventual loss via leaching. The fertiliser application on phosphate dynamics resulted in increased DIP leaching. P concentrations observed in the manufactured soil were within the range considered sufficient to support plant growth. However, the mean leached phosphorus concentrations were higher than reported eutrophication thresholds suggesting that these soils may pose a risk to surface waters in their current form.

Biochar improves fertility in waste derived manufactured soils, but not resilience to climate change.

We present a soil manufactured from waste materials, which could replace the use of peat and topsoil in plant production and reduce the pressure on natural soil resources. We tested the effect of the manufactured soil on ecosystem functions and microbial communities with and without plants present, and with and without biochar addition (Experiment 1). The resilience of the soil in response to drought and flooding, and also the effect of biochar was also tested (Experiment 2). Biochar increased soil C and N regardless of plant presence and negated the effect of the plant on soil peroxidase enzyme activity. The manufactured soil was largely resilient to drought, but not flooding, with negative impacts on microbial communities. Results indicate that biochar could improve soil properties, but not resilience to climatic perturbations. Results suggest that manufactured soils amended with biochar could offer a useful alternative to natural soil in many contexts.

Different feedstocks of biochar affected the bioavailability and uptake of heavy metals by wheat (Triticum aestivum L.) plants grown in metal contaminated soil.

Heavy metals (HMs) contamination of agricultural soils is an emerging food safety challenge at world level. Therefore, as a possible treatment for the remediation of a HMs contaminated soil (sewage water irrigation for 20-years), the impact of biochar (BC) was investigated on the uptake of HMs by wheat (Triticum aestivum L.) plants. The BC was produced from seven different feedstocks (cotton stalks (CSBC), rice straw (RSBC), poultry manure (PMBC), lawn grass (LGBC), vegetable peels (VPBC), maize straw (MSBC), and rice husks (RHBC)). Each BC was applied at 1.25% (dry weight basis, w/w) in contaminated soil and a control was maintained without BC addition and wheat was grown in potted soil and harvested at maturity. Results revealed that the properties of different biochars regulated their effects on soil nutrient and HMs mobility and uptake by plants. The maximum plant phosphorous and potassium uptake and translocation to grain (173.4% and 341%, respectively) was found in RSBC treatment over control. The RHBC, PMBC, and MSBC treatments showed a maximum decrease in grain Cd concentration (32.9%, 33.8%, and 34.1%, respectively) compared to the control. The grain Pb (-41% to -51%, with no significant differences among different treatments) and Ni (-63%) concentrations were also reduced significantly following BC treatments compared to control. The daily intake and health risk index of Cd were significantly decreased due to PMBC (-28.1% and -33.8%, respectively), and MSBC (-28.3% and -34.1%, respectively) treatment over control. The BC treatments significantly increased the translocation factor of Cd in the order of VPBC (52.1%) > LGBC (25.4%) > CSBC (13.6%) > RSBC (12.1%) compared to control. The study demonstrated that the effects of BC on metal uptake in plants varied with feedstocks and suitable BC can be further exploited for the rehabilitation of contaminated soils and thereby ensuring food safety.

Physico-chemical factors controlling the speciation of phosphorus in English and Welsh rivers.

Phosphorus is a finite resource essential for global food production. However, excessive loss to river systems from diffuse sources (typically agricultural) and point sources (e.g. waste water treatment works and industrial effluent) can lead to negative environmental impacts, including changes to diatom and invertebrate community structure. Current environmental quality standards for phosphorus in the UK have been based on reactive phosphorus, which is poorly defined and comprises an unknown proportion of soluble reactive phosphorus and chemically extractable particulate phosphorus. This research assesses the influencing factors that may control soluble reactive phosphorus concentrations in rivers, including dissolved iron, as well as partitioning processes associated with the presence of total suspended solids, and questions the reliability of the assumptions used when setting environmental quality standards. The extensive phosphorus speciation monitoring carried out across a wide geographic area of England and Wales shows that not all phosphorus as measured by the molybdenum blue method is either soluble or necessarily bioavailable, particularly at concentrations in the range in which the Environmental Quality Standard for 'Good' status (typically less than 100 µg P L-1) has been set. Phosphorus speciation can change due to physico-chemical processes which vary spatially and/or temporally, including precipitation with iron and partitioning with suspended solids.

Biochar incorporation increased nitrogen and carbon retention in a waste-derived soil.

The synthesis of manufactured soils converts waste materials to value-added products, alleviating pressures on both waste disposal infrastructure and topsoils. For manufactured soils to be effective media for plant growth, they must retain and store plant-available nutrients, including nitrogen. In this study, biochar applications were tested for their ability to retain nitrogen in a soil manufactured from waste materials. A biochar, produced from horticultural green waste, was added to a manufactured soil at 2, 5 and 10 % (by weight), then maintained at 15 °C and irrigated with water (0.84 mL m-2 d-1) over 6 weeks. Total dissolved nitrogen concentrations in soil leachate decreased by 25.2, 30.6 and 44.0 % at biochar concentrations of 2, 5 and 10 %, respectively. Biochar also changed the proportions of each nitrogen-fraction in collected samples. Three mechanisms for biochar-induced nitrogen retention were possible: i) increased cation and anion exchange capacity of the substrate; ii) retention of molecules within the biochar pore spaces; iii) immobilisation of nitrogen through microbial utilisation of labile carbon further supported by increased soil moisture content, surface area, and pH. Dissolved organic carbon concentrations in leachate were reduced (-34.7 %, -28.9 %, and -16.7 %) in the substrate with 2, 5 and 10 % biochar additions, respectively. Fluorescein diacetate hydrolysis data showed increased microbial metabolic activity with biochar application (14.7 ±â€¯0.5, 25.4 ±â€¯5.3, 27.0 ±â€¯0.1, 46.1 ±â€¯6.1 µg FL g-1 h-1 for applications at 0, 2, 5, and 10 %, respectively), linking biochar addition to enhanced microbial activity. These data highlight the potential for biochar to suppress the long-term turnover of SOM and promote carbon sequestration, and a long-term sustainable growth substrate provided by the reuse of waste materials diverted from landfill.

Natural history of eosinophilic esophagitis: a systematic review of epidemiology and disease course.

Eosinophilic esophagitis is a chronic immune-mediated esophageal disorder. For its timely diagnosis, clinicians must recognize common symptoms, and understand differences in symptoms across patient groups. The aim of this study is to systematically review the epidemiology and natural history of eosinophilic esophagitis. The MEDLINE, Embase, and Cochrane databases were searched from 1974 to February 2017 for studies describing the epidemiology and natural history of eosinophilic esophagitis. Congress abstracts from 2014 to 2016 were also searched. Search results were screened against predetermined inclusion/exclusion criteria by two independent reviewers, and data extraction was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Of 1376 articles identified, 47 met the inclusion criteria: 20 on epidemiology and 27 on natural history. Incidence and prevalence of eosinophilic esophagitis varied widely across North America and Europe, and increased over time. Incidence increased 131-fold in the Netherlands (1996-2010), 20-fold in Denmark (1997-2006), and 5.1-fold in Calgary, Canada (2004-2008). The most commonly reported symptoms were emesis and abdominal pain in children, and dysphagia and food impaction in adults. Age at diagnosis was 5.9-12.0 years in children, and approximately 30 years in adults. Time between symptom onset and diagnosis was 1.2-3.5 years in children and 3.0-8.0 years in adults. Diagnostic delay was associated with an increased risk of endoscopic features of fibrostenosis. Symptoms of eosinophilic esophagitis differed significantly by age and race. In conclusion, there is an increasing incidence and prevalence of eosinophilic esophagitis. The considerable delay between symptom onset and diagnosis suggests that clinicians do not readily recognize the disease, which may have important clinical ramifications.

Modelling of bacterial growth with shifts in temperature using automated methods with Listeria monocytogenes and Pseudomonas aeruginosa as examples.

Time to detection (TTD) measurements using turbidometry allow a straightforward method for the measurement of bacterial growth rates under isothermal conditions. Growth rate measurements were carried out for Listeria monocytogenes at 25, 30 and 37°C and for Pseudomonas aeruginosa over the temperature range 25 to 45°C. The classical three-parameter logistic model was rearranged to provide the theoretical foundation for the observed TTD. A model was subsequently developed for the analysis of TTD data from non-isothermal studies based on the Malthusian approximation of the logistic model. The model was able to predict the TTD for cultures of L. monocytogenes or P. aeruginosa undergoing simple temperature shunts (e.g. 25 to 37°C and vice versa), and for a multiple temperature shunt for L. monocytogenes (25-37-25-37°C and 37-25-37-25°C) over a period of 24h. In no case did a temperature shunt induce a lag.

Growth curve prediction from optical density data.

A fundamental aspect of predictive microbiology is the shape of the microbial growth curve and many models are used to fit microbial count data, the modified Gompertz and Baranyi equation being two of the most widely used. Rapid, automated methods such as turbidimetry have been widely used to obtain growth parameters, but do not directly give the microbial growth curve. Optical density (OD) data can be used to obtain the specific growth rate and if used in conjunction with the known initial inocula, the maximum population data and knowledge of the microbial number at a predefined OD at a known time then all the information required for the reconstruction of a standard growth curve can be obtained. Using multiple initial inocula the times to detection (TTD) at a given standard OD were obtained from which the specific growth rate was calculated. The modified logistic, modified Gompertz, 3-phase linear, Baranyi and the classical logistic model (with or without lag) were fitted to the TTD data. In all cases the modified logistic and modified Gompertz failed to reproduce the observed linear plots of the log initial inocula against TTD using the known parameters (initial inoculum, MPD and growth rate). The 3 phase linear model (3PLM), Baranyi and classical logistic models fitted the observed data and were able to reproduce elements of the OD incubation-time curves. Using a calibration curve relating OD and microbial numbers, the Baranyi equation was able to reproduce OD data obtained for Listeria monocytogenes at 37 and 30°C as well as data on the effect of pH (range 7.05 to 3.46) at 30°C. The Baranyi model was found to be the most capable primary model of those examined (in the absence of lag it defaults to the classic logistic model). The results suggested that the modified logistic and the modified Gompertz models should not be used as Primary models for TTD data as they cannot reproduce the observed data.

A framework for the evaluation of chemical structure databases.

Access to desk-top structure and reaction databases through applications such as Chemical Abstracts' SciFinder, MDL's Beilstein CrossFire, and ISIS Reaction Browser has led to changes in information seeking habits of research chemists, the impact of which has implications when database purchasing decisions are made. A semiquantitative assessment is proposed which takes into account key aspects of structure and reaction databases. Assessment criteria are identified which can be weighted according to an organization's information needs. Values are then assigned to criteria for each data source, after which a formula is applied which leads to an indication of the relative value of systems under consideration. The formula takes into account the cost of database products and also the incremental benefit of adding a new system to an existing collection. This work is presented as a generic approach to the evaluation of databases and is not limited in scope to only structure and reactions databases.

Health and well-being of women family carers: a comparative study with a generic focus.

OBJECTIVE: To examine differences between women family carers of people with chronic illnesses or disabilities and a group of women 'non-carers' in self-reported physical health, psychological well-being, life satisfaction, social support and feelings of overload. METHOD: Using a computer-assisted telephone interviewing system, a random survey of more than 26,000 households was conducted in Victoria to identify and then interview a representative sample of family carers of people with disabilities or chronic illnesses. The women in the sample (n = 857) were then compared with a sample of women with 'usual family responsibilities' (n = 219) in terms of physical and emotional states. RESULTS: We found higher rates of self-reported ill-health and use of medication, more negative effect, and less life satisfaction and perceived social support, among carers than among women in the comparison group. Even though the latter were more likely to be caring for one or more children, compared with the carers they reported less overload. Irrespective of carers status, women without partners expressed less life satisfaction, and more social isolation and negative effect. CONCLUSIONS AND IMPLICATIONS: The poorer health status and emotional well-being of carers compared with non-carers among women, and associations between overload, social isolation, negative effect and health problems within carers, point to a number of practical interventions such as promoting an awareness in GPs and other health professionals of the impact of caregiving on the health of their patients; informing them about relevant community services; and encouraging appropriate referrals.

Caregiving: a common or uncommon experience?

The analysis reported here aims to establish the household prevalence of caregiving in Australia, drawing on a large scale, longitudinal survey conducted as part of the Victorian Carers Project. Comparisons are made with a national survey conducted by the Australian Bureau of Statistics and with Canadian and U.K. findings. Three aspects of caregiving are investigated: reported household prevalence, taking account of differences in definitions used in various surveys; the extent of intergenerational exchanges involved in caregiving; and the time dimensions of caregiving, in terms of duration and patterns of cessation of caregiving over time. A high degree of consistency is found in prevalences of caregiving and implications for the development of policies and programs to support caregivers are raised concerning levels of caregiving, approaches to identifying carers, targeting of services and promotion of caregiving, and the spread of the experience of caregiving across the lifecycle and between generations.

The role of general practitioners and pharmacists in information exchange with family carers.

As a trial of the provision of community-service information to family carers, general practitioners and pharmacists from the Western region of Melbourne were supplied with tear-off pads listing suburb-specific community services, and were encouraged to discuss service needs with carers of people with disabilities and distribute the lists to carers accordingly. One hundred and nine general practitioners and 58 pharmacists participated in pretrial and post-trial interviews assessing their knowledge of community services and frequency of discussion with carers. Before the trial, general practitioners had significantly higher self-rated knowledge of community services and reportedly discussed these with carers more often than did pharmacists. After the five-month trial period, pharmacists showed a significant increase in self-rated knowledge and frequency of discussion. General practitioners' knowledge and discussion showed a nonsignificant increase. After the trial, the two did not differ in knowledge of services; however, general practitioners maintained a higher reported frequency of discussion about services with carers. General practitioners and pharmacists appear to be well placed to act as a service link for family carers. However, additional high-intensity strategies are needed to assist them in this role.

Family caregiving: measurement of emotional well-being and various aspects of the caregiving role.

BACKGROUND: Past research and instrument development in caregiving have focused on specific aspects of caregiving or specific disability groups. This paper reports the scale characteristics of a new generic instrument developed to assess the experience of caregiving, and the social and emotional well-being of caregivers and a comparison group of 'non-caregivers'. METHODS: Using computer-assisted telephone technology, a random survey of 26000 households was conducted in Victoria, Australia to identify and interview 976 caregivers of people who were aged or had a long-term illness or disability of any kind, and 219 non-caregivers. Both groups were re-interviewed after 15 months. Scales administered on each occasion to caregivers and non-caregivers included life satisfaction, positive and negative affect, social support and overload; and to caregivers, caring role satisfaction, resentment and anger, and, in relation to the care recipient, measures of help provided and needed, severity of disability and behaviour problems. RESULTS: On each occasion and with each sample all scales demonstrated a satisfactory reliability. With a subsample of caregiver-care-recipient dyads (N = 67), caregiver reports of severity of disability, level of helped needed and provided were validated externally by clinician assessments. CONCLUSIONS: A comprehensive instrument to assess the experience of caregiving was developed. It is relevant to a broad range of ages, levels and types of disability and care provided; and, in assessing health and well-being, to both caregivers and non-caregivers. Scales, including both positive and negative dimensions, have demonstrated good internal consistency on two occasions. The instrument is potentially useful in a range of research and practical settings.

A profile of Australian family caregivers: diversity of roles and circumstances.

Research on family caregiving has been based largely on small samples, often drawn from support organisations or services, and has tended to focus on particular disability groups. Our study was population-based and included all ages and disabilities. As the first stage in a longitudinal research and health promotion program for informal caregivers, a statewide random survey of over 26,000 households was conducted by telephone: 78 per cent of self-identified carers (N = 976) agreed to participate in a one-hour interview. This paper presents a sociodemographic profile of Australian caregivers. Four types of relationship between carers and care recipients (adult offspring, spouses, parents and other relatives and friends) provide the framework for results. Group differences were observed on most characteristics: for example, age, living arrangements, work status and duration of care. Care recipient characteristics, including difficult behaviours and need for assistance, are also reported, as well as use of and need for community services. What the findings reflected most was the heterogeneity of both caregivers and care recipients and the diversity of caregiving roles and circumstances.

Home-based assessment for family carers: a preventative strategy to identify and meet service needs.

OBJECTIVE: To identify unmet need for services among family carers and their frail or disabled relatives and to facilitate links to services. DESIGN: Intervention study with a subgroup of carer dyads from a random statewide survey of family carers, followed by telephone 2 months post intervention. SETTING: Carer dyads in general community; urban and rural Victoria. PARTICIPANTS: All 186 identified carers were approached. One-third of the dyads were ineligible; of the remainder, 67 (53%) participated, matching refusals on sociodemographic characteristics. Carers were typically married, middle-aged women looking after parents or spouses. Almost half of the care recipients were aged > or = 80; most had multiple disorders and impairments. Follow-up rate was 94%. INTERVENTION: One off, multidisciplinary home-based assessment of dyad by research team and regional aged care assessment service (ACAT). MAIN OUTCOME MEASURES: "Unmet need': % dyads recommended new services; number services per dyad via ACAT; increases in service range; extension of pre-existing services. Service linkage: % dyads linked to new services; perceived usefulness of linkages. MAIN RESULTS: Dyads recommended a new service (93%); increased range (73%); extensions (41%). Average two services requiring ACAT implementation; commonly respite care, aids and paramedical services. Recommendations related to impairment severity and carer stress. ACAT implemented recommendations (90% relevant dyads); links rated useful (75% relevant dyads). Three-quarters of the carers rated intervention as helpful. CONCLUSION: A preventative programme of needs assessment for carer dyads has considerable potential; (a) identifying needs and engaging new services; (b) providing emotional support.

Information for family carers: does it help?

Family carers in Victoria were identified through a statewide telephone survey in 1993. A total of 976 carers was interviewed and a random sample of approximately one in 10 (n = 103) were offered the Carer Support Kit leaflet. The leaflet details the components of the Carer Support Kit (a Federal Government initiative developed in 1992-93) and informs carers how to apply for it through the Victorian Carers' Association. Approximately three-quarters of these carers accepted the offer, and around a third subsequently applied for the kit. Carers who applied for the kit reported significantly more overload and lower life satisfaction than those who did not apply. Only two-thirds of those mailed the kit (just 23 per cent of the eligible study sample) went on to use it. Those who had not used it reported significantly more negative emotions and health problems than those who used it, suggesting that stress and crises could preclude utilisation of the information. A brief evaluation of the components of the kit is presented; however, findings need to be treated with caution in view of the small sample size.