De invloeden van wet- en regelgeving op innovatie in de primaire sector

Innovatie is het toverwoord van de hedendaagse economie, de agrarische sector niet uitgezonderd. Door middel van innovatie behouden bedrijven hun concurrentiekracht en worden maatschappelijke dilemma's opgelost

Innoveren onder voorwaarden : hoe wetten en regels de innovatiemogelijkheden van de agrarisch ondernemer beonvloeden

Dit rapport verschaft inzicht in de wijze waarop wet- en regelgeving de innovativiteit van de agrarische ondernemingen beïnvloedt. We zien dat de grote mate van detail in de huidige wet- en regelgeving een groot struikelblok is voor vooruitstrevende ondernemers. Onverwachte wijzigingen in wet- en regelgeving en inconsistenties tussen verschillende wetten en regels zijn andere problemen waar de vooruitstrevende ondernemer mee kampt. Het Ministerie van LNV zal zich terdege bewust moeten zijn van bepaalde aspecten van innovatie in de agrarische sector, zoals de diversiteit onder ondernemers, de inherente onzekerheid rond innovatieprojecten enzovoort. Goede communicatie vanuit de overheid over het doel van wet- en regelgeving is van groot belan

Een hernieuwde kijk op individuele besluitvorming in de glastuinbouw

In dit rapport wordt verslag gedaan van een verkennend onderzoek naar verschillen in de besluitvorming van individuele glastuinders en naar de rol die de 'omgeving' hierbij speelt. Onderzoeksvragen zijn: Hoe verloopt het besluitvormingsproces van een glastuinder bij investeringsbeslissingen omtrent energiebesparing? Wat is de rol van 'externen' (bedrijfs-adviseurs, collega-telers, en dergelijke) bij dit proces? Hoe krijgen we zicht op de interactie tussen de glastuinder en zijn of haar omgeving? Op basis van de literatuur is een conceptueel model opgesteld. Bij in totaal 70 glastuinders zijn, via een workshop en telefonische interviews, data verzameld met be-trekking tot persoonlijkheidskenmerken, attituden en informatieverzamelingsgedrag. Deze data zijn vervolgens gerelateerd aan hun bedrijfsgegevens die reeds eerder vastgelegd zijn in het Bedrijven-Informatienet van LEI B.V. De resultaten laten zien dat er significante relaties zijn tussen persoonlijkheidskenmerken van glastuinders, bedrijfsfactoren en informatieverzamelingsgedrag. Het persoonlijkheidskenmerk 'extraversie' en de bedrijfsfactor 'oppervlakte van het bedrijf' ble-ken (deels) te kunnen verklaren waarom de ene glastuinder zelf de uiteindelijke beslissing neemt en de andere glastuinder het overlaat aan een 'extern' persoon

Antimutagenic activity of green tea and black tea extracts studied in a dynamic in vitro gastrointestinal model

An in vitro gastrointestinal model, which simulates the conditions in the human digestive tract, was used to determine potential antimutagenic activity of extracts of black tea and green tea. In this paper, results are presented on the availability for absorption of potential antimutagenic compounds present in tea and on the influence of the food matrix on this activity. Between 60 and 180 min after the tea was introduced into the model, antimutagenic activity was recovered from the jejunal compartment by means of dialysis: the dialysate appeared to inhibit the mutagenicity of the food mutagen MeIQx in the direct plate assay with Salmonella typhimurium (Ames test). The maximum inhibition was measured at 2 h after the start of the experiment and was comparable for black tea and green tea extract. To determine the influence of food matrices on the antimutagenic activity of tea, the model was loaded with black tea together with milk or a homogenized standard breakfast. The maximum inhibition observed with black tea was reduced by 22, 42 and 78% in the presence of whole milk, semi-skimmed milk, and skimmed milk, respectively. Whole milk and skimmed milk abolished the antimutagenic activity of green tea by more than 90%; for semi-skimmed milk the inhibition was more than 60%. When a homogenized breakfast was added into the model together with the black tea extract, the antimutagenic activity was completely eliminated. When tea and MeIQx were added together into the digestion model, MeIQx mutagenicity was efficiently inhibited, with green tea showing a slightly stronger antimutagenic activity than black tea. In this case, the addition of milk had only a small inhibiting effect on the antimutagenicity. Antioxidant capacity and the concentration of catechins were also measured in the jejunal dialysates. The reduction in antimutagenic activity corresponded with reduction in antioxidant capacity and with a decrease of concentration of three catechins, viz. catechin, epigallocatechin gallate and epigallocatechin. The in vitro gastrointestinal model appears to be a useful tool to study the antimutagenicity of food components. © 2001 Elsevier Science B.V.Chemicals/CAS: Antimutagenic Agents; Antioxidants; Plant Extract

Estimation of Multiple Inflows and Effective Channel by Assimilation of Multi-satellite Hydraulic Signatures: The Ungauged Anabranching Negro River

International audienceWith the upcoming SWOT satellite mission, which should provide spatially dense river surface elevation, width and slope observations globally, comes the opportunity to assimilate such data into hydrodynamic models, from the reach scale to the hydrographic network scale. Based on the HiVDI (Hierarchical Variational Discharge Inversion) modeling strategy (Larnier et al. [#Larnier2019]), this study tackles the forward and inverse modeling capabilities of distributed channel parameters and multiple inflows (in the 1D Saint-Venant model) from multisatellite observations of river surface. It is shown on synthetic cases that the estimation of both inflows and distributed channel parameters (bathymetry-friction) is achievable with a minimum spatial observability between inflows as long as their hydraulic signature is sampled. Next, a real case is studied: 871 km of the Negro river (Amazon basin) including complex multichannel reaches, 21 tributaries and backwater controls from major confluences. An effective modeling approach is proposed using (i) WS elevations from ENVISAT data and dense in situ GPS flow lines (Moreira [#DanielPhD]), (ii) average river top widths from optical imagery (Pekel et al. [#Pekel_Nature]), (iii) upstream and lateral flows from the MGB large-scale hydrological model (Paiva et al. [#paiva2013]). The calibrated effective hydraulic model closely fits satellite altimetry observations and presents real like spatial variabilities; flood wave propagation and water surface observation frequential features are analyzed with identifiability maps following Brisset et al. [#Brisset_2018]. Synthetic SWOT observations are generated from the simulated flowlines and allow to infer model parameters (436 effective bathymetry points, 17 friction patches and 22 upstream and lateral hydrographs) given hydraulically coherent prior parameter values. Inferences of channel parameters carried out on this fine hydraulic model applied at a large scale give satisfying results using noisy SWOT-like data at reach scale. Inferences of spatially distributed temporal parameters (lateral inflows) give satisfying results as well, with even relatively small scale hydrograph variations being inferred accurately on this long reach. This study brings insights in: (i) the hydraulic visibility of multiple inflows hydrographs signature at large scale with SWOT; (ii) the simultaneous identifiability of spatially distributed channel parameters and inflows by assimilation of satellite altimetry data; (iii) the need for prior information; (iv) the need to further tailor and scale network hydrodynamic models and assimilation methods to improve the fusion of multisource information and potential information feedback to hydrological modules in integrated chains