Population dynamics of free-swimming Annelida in four Dutch wastewater treatment plants in relation to process characteristics

Free-swimming Annelida occasionally occur in very high densities in WWTPs (WasteWater Treatment Plants) and are nowadays applied for waste sludge reduction, but their growth is uncontrollable. In order to get more insight in the population dynamics of these free-swimming Annelida, and relate their presence to process characteristics, nine ATs (Aeration Tanks) of four Dutch WWTPs were regularly sampled over a 2.5-year period. For each species, peak periods in worm population growth were defined and population doubling times and half-lives calculated. Peak periods and doubling times were compared to those in natural systems. Process characteristics were obtained from the plant operators and related to the worm populations by multivariate analysis for the first time in large-scale WWTPs. The species composition in the WWTPs was limited and the most abundant free-swimming Annelida were in decreasing order Nais spp., Aeolosoma hemprichi, Pristina aequiseta, Aeolosoma variegatum, Chaetogaster diastrophus, and Aeolosoma tenebrarum.This latter species had never been found before in WWTPs. Worm absence sometimes coincided with the presence of anoxic zones, but this was possibly overcome by higher temperatures in the WWTPs. Worms were present all year round, even in winter, but no yearly recurrences of population peaks were observed, probably as a result of stable food supply and temperature, and the lack of predation in the WWTPs. Peak periods were similar between the ATs of each WWTP. The duration of the peak periods was on average 2¿3 months for each species and the population doubling times in the peak periods were short (on average 2¿6 days), which also corresponds to a stable favorable environment. The disappearance of worm populations from the WWTPs was presumably caused by declining asexual reproduction and subsequent removal with the waste sludge. Multivariate analysis indicated that 36% of the variability in worm populations was due to spatial and temporal patterns only. In addition, no more than 4% of the variability in worm populations was related to variations in process characteristics only and worm presence was usually associated with better sludge settleability. In conclusion, our data from large-scale WWTPs suggest that growth of free-swimming Annelida still seems uncontrollable and that their effects on treatment processes are unclear, which makes stable application in wastewater treatment for sludge reduction difficult

Context, mechanisms and outcomes of integrated care for diabetes mellitus type 2:A systematic review

Background: Integrated care interventions for chronic conditions can lead to improved outcomes, but it is not clear when and why this is the case. This study aims to answer the following two research questions: First, what are the context, mechanisms and outcomes of integrated care for people with type 2 diabetes? Second, what are the relationships between context, mechanisms and outcomes of integrated care for people with type 2 diabetes? Methods: A systematic literature search was conducted for the period 2003-2013 in Cochrane and PubMed. Articles were included when they focussed on integrated care and type 2 diabetes, and concerned empirical research analysing the implementation of an intervention. Data extraction was performed using a common data extraction table. The quality of the studies was assessed with the Mixed Methods Appraisal Tool. The CMO model (context + mechanism = outcome) was used to study the relationship between context factors (described by the barriers and facilitators encountered in the implementation process and categorised at the six levels of the Implementation Model), mechanisms (defined as intervention types and described by their number of Chronic Care Model (sub-) components) and outcomes (the intentional and unintentional effects triggered by mechanism and context). Results: Thirty-two studies met the inclusion criteria. Most reported barriers to the implementation process were found at the organisational context level and most facilitators at the social context level. Due to the low number of articles reporting comparable quantitative outcome measures or in-depth qualitative information, it was not possible to make statements about the relationship between context, mechanisms and outcomes. Conclusions: Efficient resource allocation should entail increased investments at the organisational context level where most barriers are expected to occur. It is likely that investments at the social context level will also help to decrease the development of barriers at the organisational context level, especially by increasing staff involvement and satisfaction. If future research is to adequately inform practice and policy regarding the impact of these efforts on health outcomes, focus on the actual relationships between context, mechanisms and outcomes should be actively incorporated into study designs

Disease suppression in cress and sugar beet seedlings with frass of the Black Soldier Fly (Hermetia illucens)

This report describes two bioassays for testing disease suppression by BSF frass in an agricultural soil with two crops: sugar beet (Beta vulgaris) and cress (Lepidium sativum). In the bioassay with beet, soil was infected with the plant-pathogenic fungus Rhizoctonia solani while in the bioassay with cress, soil was non-infected or infected with the plant-pathogenic fungus Pythium ultimum. Both concentrations of the BSF frass (7.5 and 15 g/kg soil) proved to be useful as soil application, leading to good plant emergence and growth of sugar beet and cress plants. The highest concentration of BSF frass (15 g/kg soil, both as total product) had a large fertilizer effect. In experiments with cress without addition of Pythium (i.e. with only natural soil infections), disease suppression with BSF frass was found. In all tests, keratin was added as a positive control treatment, which had a higher disease suppression effect than BSF frass but comparable fertilizer effects

Productie van zoutwateralgen voor toepassingen in food (en feed) deelrapport I : Werkpakketten 1&2 van project Foodgrade productie van zoutwateralgen: deelrapport I: Achtergrondinformatie zoutwateralgen: selectie van soorten en omgevingsomstandigheden

The commercial production of microalgae for food applications has been the focus of much attention lately. Culturing marine microalgae in reactors with LED lamps has several advantages. Marine algae contain valuable components such as antioxidants, which are described in this report, and high salinities in production systems can lead to less contamination. By producing them in closed systems at different LED light wavelengths (colours) high biomass concentrations can be obtained and production of biomass and valuable components can be increased. This report summarizes interesting components (i.e. pigments, lipids, carbohydrates) from marine microalgae in addition to general effects of light, nutrients, salt, pressure and mutations on algae growth. The influence of several parameters on biomass growth and pigment formation of several commercially interesting marine algae species is described. These parameters include light intensity, wavelength, light path length, nitrogen source and concentration, mutagens, dilution/refreshment rates, mixing conditions, temperature, salt concentration, flashing (alternating L/D cycles), mixotrophic/phototrophic conditions, alternative nutrient sources, mixed cultures and Si addition. Species that are described in detail include Dunaliella salina and tertiolecta, Arthrospira platensis, Nannochloropsis gaditana and sp., Phaeodactylum tricornutum, Porphyridium purpureum, Tetraselmis chuii, Odontella aurita and Odontella sinensis

Advancing current approaches to disease management evaluation:Capitalizing on heterogeneity to understand what works and for whom

BACKGROUND: Evaluating large-scale disease management interventions implemented in actual health care settings is a complex undertaking for which universally accepted methods do not exist. Fundamental issues, such as a lack of control patients and limited generalizability, hamper the use of the ‘gold-standard’ randomized controlled trial, while methodological shortcomings restrict the value of observational designs. Advancing methods for disease management evaluation in practice is pivotal to learn more about the impact of population-wide approaches. Methods must account for the presence of heterogeneity in effects, which necessitates a more granular assessment of outcomes. METHODS: This paper introduces multilevel regression methods as valuable techniques to evaluate ‘real-world’ disease management approaches in a manner that produces meaningful findings for everyday practice. In a worked example, these methods are applied to retrospectively gathered routine health care data covering a cohort of 105,056 diabetes patients who receive disease management for type 2 diabetes mellitus in the Netherlands. Multivariable, multilevel regression models are fitted to identify trends in clinical outcomes and correct for differences in characteristics of patients (age, disease duration, health status, diabetes complications, smoking status) and the intervention (measurement frequency and range, length of follow-up). RESULTS: After a median one year follow-up, the Dutch disease management approach was associated with small average improvements in systolic blood pressure and low-density lipoprotein, while a slight deterioration occurred in glycated hemoglobin. Differential findings suggest that patients with poorly controlled diabetes tend to benefit most from disease management in terms of improved clinical measures. Additionally, a greater measurement frequency was associated with better outcomes, while longer length of follow-up was accompanied by less positive results. CONCLUSIONS: Despite concerted efforts to adjust for potential sources of confounding and bias, there ultimately are limits to the validity and reliability of findings from uncontrolled research based on routine intervention data. While our findings are supported by previous randomized research in other settings, the trends in outcome measures presented here may have alternative explanations. Further practice-based research, perhaps using historical data to retrospectively construct a control group, is necessary to confirm results and learn more about the impact of population-wide disease management

Bioconversie van digestaat door wormen: productie van eiwit en compost

Dit rapport beschrijft groei op en omzetting van de dikke fractie (28 % droge stof) van digestaat door E. fetida wormen (compostwormen) in 6 kweekbedden van elk 5 m2. De begindichtheid van de wormen was 5 kg/m2. Het digestaat was afkomstig uit de ACRRES vergister die gevoed werd met rundermest en natuurgras. In de vijf weken durende proef bij Lumbriculus te Oostwold werd het voorgecomposteerde digestaat continu omgezet in wormencompost waarbij 22 % (natgewicht) van het digestaat afgebroken werd. De omzettingssnelheid was 1.6-3.2 kg (3.2-6.4 L) per kg levende wormen (per m2) per week. Door het opeten van het digestaat veranderden structuur van en nutriënten in het digestaat: De ontstane wormencompost had een korrelige lichte structuur en ammoniak nam bijvoorbeeld met 65 % af. Ook groeiden de wormen in biomassa en produceerden ze cocons. De gemiddelde groei in natte wormenbiomassa was 4 % per week. De maximale snelheden werden nog niet bereikt in dit experiment, maar het is duidelijk dat vermicompostering tot een substantiële afbraak van de dikke fractie van digestaat leidt en de productie van een nieuwe meststof (wormencompost) en nieuw eiwit (wormenbiomassa)

The effectiveness of chronic care management for heart failure: meta-regression analyses to explain the heterogeneity in outcomes

Objective: To support decision making on how to best redesign chronic care by studying the heterogeneity in effectiveness across chronic care management evaluations for heart failure.\ud \ud Data Sources: Reviews and primary studies that evaluated chronic care management interventions.\ud \ud Study design: A systematic review including meta-regression analyses to investigate three potential sources of heterogeneity in effectiveness: study quality, length of follow-up, and number of Chronic Care Model (CCM) components.\ud \ud Principal findings: Our meta-analysis showed that chronic care management reduces mortality by a mean of 18% (95% CI: 0.72-0.94) and hospitalization by a mean of 18% (95% CI: 0.76-0.93) and improves quality of life by 7.14 points (95% CI: -9.55 - -4.72) on the Minnesota Living with Heart Failure questionnaire. We could not explain the considerable differences in hospitalization and quality of life across the studies.\ud \ud Conclusion: Chronic care management significantly reduces mortality. Positive effects on hospitalization and quality of life were shown, however, with substantial heterogeneity in effectiveness. This heterogeneity is not explained by study quality, length of follow-up, or the number of CCM components. More attention to the development and implementation of chronic care management is needed to support informed decision making on how to best redesign chronic care

Productie van zoutwateralgen voor toepassingen in food (en feed) deelrapport II : Werkpakketten 1&2 van project Foodgrade productie van zoutwateralgen: deelrapport II: Batchexperimenten met zoute reststromen en verschillende mariene algensoorten

There is a lot of interest in the commercial production of microalgae for food applications. Producing marine microalgae in reactors with LED lights has several advantages. Marine microalgae contain valuable components such as antioxidants, and high salinity levels in production systems can prevent contaminations with other organisms. Production in closed systems at different light wavelengths (colours) can result in high biomass concentrations and better control of biomass growth and production of valuable components. Several industries produce salt waste streams, often with associated processing costs. In this report a number of these streams is discussed (liquid fraction of cattle manure biogas slurry, potassium and sodium brines from dairy industries, brackish groundwater, seawater, purge water and brine from salt processing). An option for reducing costs (for disposal or treatment) is the production of marine microalgae on these streams. The algae can be used as food (ingredient). This report describes batch experiments in which growth of nine microalgae species was tested on these waste streams: Nannochloropsis gaditana, Phaeodactylum tricornutum, Tetraselmis chuii (two strains), Porphyridium purpureum, Dunaliella salina, Odontella aurita, Arthrospira platensis and Tetraselmis tetrathele. The experiments were performed in well plates and 1 L reactors with artificial (LED) lights. From the tests it was concluded that several of the algae species can be cultured on different waste streams. The best results were obtained with N. gaditana, A. platensis, P. purpureum en T. chuii (AF&F) on (diluted) brines from the dairy industry and the diluted liquid fraction of biogas slurry. It is recommended to optimize some of these combinations further in experiments