Draining Sustainable Profit Fase 1: deskstudie naar mogelijkheden voor benutting van drainwater voor het kweken van algen voor oesterteelt

Drainwater dat vrij komt in de glastuinbouw bevat zouten en voedingsstoffen die bij lozing een belasting op de watersystemen geven, hetgeen lozingsheffingen met zich meebrengt en waardoor tevens waardevolle nutriënten verloren gaan. De uitdaging van het reduceren van de milieubelasting ligt in het hergebruiken van de nutriënten, waardoor een kostenpost kan worden omgezet in een renderende reststroom. Het (beperkte) zoutgehalte (3 ppt of in geconcentreerde vorm 12 ppt) van het drainwater maakt het water mogelijk geschikt voor de kweek van brakwater (en adaptieve mariene) algensoorten. Hierdoor worden waardevolle nutriënten onttrokken en wordt de anorganische belasting van het drainwater lager. Het gekweekte algenproduct kan geschikt zijn voor een aanvullende teelt van een aquacultuurproduct zoals schelpdieren, deze kunnen aan elkaar gekoppeld worden. Aangezien dergelijke mogelijkheden nieuw zijn, bestaan er nog een aantal onbekende factoren, zoals het selecteren van geschikte soorten algen voor kweek, de voedingswaarde van de oester en voedselveiligheidsrisico’s. Deze parameters worden aan de hand van een desk studie gekoppeld aan laboratorium experimenten onderzocht

Microbial symbionts of parasitoids

Parasitoids depend on other insects for the development of their offspring. Their eggs are laid in or on a host insect that is consumed during juvenile development. Parasitoids harbor a diversity of microbial symbionts including viruses, bacteria, and fungi. In contrast to symbionts of herbivorous and hematophagous insects, parasitoid symbionts do not provide nutrients. Instead, they are involved in parasitoid reproduction, suppression of host immune responses, and manipulation of the behavior of herbivorous hosts. Moreover, recent research has shown that parasitoid symbionts such as polydnaviruses may also influence plant-mediated interactions among members of plant-associated communities at different trophic levels, such as herbivores, parasitoids, and hyperparasitoids. This implies that these symbionts have a much more extended phenotype than previously thought. This review focuses on the effects of parasitoid symbionts on direct and indirect species interactions and the consequences for community ecology

Hyperparasitoids exploit herbivore-induced plant volatiles during host location to assess host quality and non-host identity

Although consumers often rely on chemical information to optimize their foraging strategies, it is poorly understood how top carnivores above the third trophic level find resources in heterogeneous environments. Hyperparasitoids are a common group of organisms in the fourth trophic level that lay their eggs in or on the body of other parasitoid hosts. Such top carnivores use herbivore-induced plant volatiles (HIPVs) to find caterpillars containing parasitoid host larvae. Hyperparasitoids forage in complex environments where hosts of different quality may be present alongside non-host parasitoid species, each of which can develop in multiple herbivore species. Because both the identity of the herbivore species and its parasitization status can affect the composition of HIPV emission, hyperparasitoids encounter considerable variation in HIPVs during host location. Here, we combined laboratory and field experiments to investigate the role of HIPVs in host selection of hyperparasitoids that search for hosts in a multi-parasitoid multi-herbivore context. In a wild Brassica oleracea-based food web, the hyperparasitoid Lysibia nana preferred HIPVs emitted in response to caterpillars parasitized by the gregarious host Cotesia glomerata over the non-host Hyposoter ebeninus. However, no plant-mediated discrimination occurred between the solitary host C. rubecula and the non-host H. ebeninus. Under both laboratory and field conditions, hyperparasitoid responses were not affected by the herbivore species (Pieris brassicae or P. rapae) in which the three primary parasitoid species developed. Our study shows that HIPVs are an important source of information within multitrophic interaction networks allowing hyperparasitoids to find their preferred hosts in heterogeneous environments

Fork naar Farm. deelrapport: experimentele kweek van yellowtail kingfish (Seriola lalandi) en de implementatie hiervan

In Nederland is sprake van een toenemende vraag naar duurzaam en lokaal geproduceerde vis. Het doel van het Fork naar Farm project was het begeleiden van de productie van een nieuwe vissoort binnen de Nederlandse viskweeksector en Afrikaanse meerval volgens een certificeringsschema waarin duurzaamheid een rol speelt. Binnen het kader van het Fork naar Farm project behandelt dit rapport het onderzoek naar de opkweek van de yellowtail kingfish (Seriola lalandi) in recirculatiesystemen en de implementatie hiervan in de praktijk. Er zijn verschillende groepen jonge yellowtail kingfish met een gewicht van ongeveer 0,5 gram aangekocht vanuit Australië en in Nederland opgekweekt in recirculatiesystemen. Er is in de faciliteiten van IMARES Wageningen UR onderzoek verricht naar diverse houderijomstandigheden: temperatuur, pH en saliniteit van het water en het voer

Waterreservoirs op bedrijfsniveau alternatief voor zoetwatervoorziening landbouw?

De zoetwatervoorziening van de landbouw in Nederland staat hoog op de beleidsagenda. Het Rijk verbreedt het zoeken naar oplossingen voor het zoetwatervraagstuk van alleen kijken naar aanbod vanuit het hoofdwatersysteem naar ook het verkennen van de mogelijkheden voor grotere zelfvoorzienendheid. De vraag, die in dit artikel wordt behandeld, is of vasthouden van het neerslagoverschot in zoetwaterbekkens op bedrijfsniveau een redelijk alternatief vormt voor wateraanvoe

Successful Tocilizumab Treatment for Scleritis

Purpose: To present a rare case of scleritis associated with a prior diagnosis of giant cell arteritis (GCA) that was unresponsive to glucocorticoids, nonsteroidal anti-inflammatory drugs (NSAIDs), methotrexate, and azathioprine, but reached and maintained a full remission with tocilizumab. Observations: A 62-year-old Caucasian female presented with scleritis and headache. Four years earlier, the patient was diagnosed with GCA. Treatment with topical and systemic NSAIDs, prednisone and diverse disease-modifying antirheumatic drugsonly had a partial effect on the scleritis whilst the arthralgia and headaches increased. Despite the absence of laboratory evidence of active GCA, tocilizumab was started and the scleritis and headaches disappeared within several days. Prednisone could be fully tapered within 3 months and to date, 12 months after the start of tocilizumab, the patient has maintained a sustained remission. Conclusions: Our patient demonstrates that tocilizumab might represent a therapeutic option for scleritis, and its further evaluation for this severe ocular disease is worthwhile

Quasi-classical rate coefficient calculations for the rotational (de)excitation of H2O by H2

The interpretation of water line emission from existing observations and future HIFI/Herschel data requires a detailed knowledge of collisional rate coefficients. Among all relevant collisional mechanisms, the rotational (de)excitation of H2O by H2 molecules is the process of most interest in interstellar space. To determine rate coefficients for rotational de-excitation among the lowest 45 para and 45 ortho rotational levels of H2O colliding with both para and ortho-H2 in the temperature range 20-2000 K. Rate coefficients are calculated on a recent high-accuracy H2O-H2 potential energy surface using quasi-classical trajectory calculations. Trajectories are sampled by a canonical Monte-Carlo procedure. H2 molecules are assumed to be rotationally thermalized at the kinetic temperature. By comparison with quantum calculations available for low lying levels, classical rates are found to be accurate within a factor of 1-3 for the dominant transitions, that is those with rates larger than a few 10^{-12}cm^{3}s^{-1}. Large velocity gradient modelling shows that the new rates have a significant impact on emission line fluxes and that they should be adopted in any detailed population model of water in warm and hot environments.Comment: 8 pages, 2 figures, 1 table (the online material (4 tables) can be obtained upon request to [email protected]

Exploiting chemical ecology to manage hyperparasitoids in biological control of arthropod pests

Insect hyperparasitoids are fourth trophic level organisms that commonly occur in terrestrial food webs, yet they are relatively understudied. These top-carnivores can disrupt biological pest control by suppressing the populations of their parasitoid hosts, leading to pest outbreaks, especially in confined environments such as greenhouses where augmentative biological control is used. There is no effective eco-friendly strategy that can be used to control hyperparasitoids. Recent advances in the chemical ecology of hyperparasitoid foraging behavior have opened opportunities for manipulating these top-carnivores in such a way that biological pest control becomes more efficient. We propose various infochemical-based strategies to manage hyperparasitoids. We suggest that a push-pull strategy could be a promising approach to ‘push’ hyperparasitoids away from their parasitoid hosts and ‘pull’ them into traps. Additionally, we discuss how infochemicals can be used to develop innovative tools improving biological pest control (i) to restrict accessibility of resources (e.g. sugars and alternative hosts) to primary parasitoid only or (ii) to monitor hyperparasitoid presence in the crop for early detection. We also identify important missing information in order to control hyperparasitoids and outline what research is needed to reach this goal. Testing the efficacy of synthetic infochemicals in confined environments is a crucial step towards the implementation of chemical ecology-based approaches targeting hyperparasitoids. © 2019 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry