A methodology for model-based greenhouse design: Part 5, greenhouse design optimisation for southern-Spanish and Dutch conditions     

Bram H.E. Vanthoor  Johannes D. Stigter  Eldert J. van Henten  Cecilia Stanghellini  Pieter H.B. de Visser  Silke Hemming 《Biosystems Engineering》2012,111(4):350-368

  相似文献   

New insights into an ancient antibrowning agent: formation of sulfophenolics in sodium hydrogen sulfite-treated potato extracts     

Narváez-Cuenca CE  Kuijpers TF  Vincken JP  de Waard P  Gruppen H 《Journal of agricultural and food chemistry》2011,59(18):10247-10255

The effect of sodium hydrogen sulfite (S), used as antibrowning agent, on the phenolic profile of potato extracts was investigated. This extract was compared to one obtained in the presence of ascorbic acid (A). In the presence of A, two major compounds were obtained, 5-O-caffeoylquinic acid (5-CQA) and 4-O-caffeoyl quinic acid. With S, their 2'-sulfo-adducts were found instead, the structures of which were confirmed by nuclear magnetic resonance spectroscopy and mass spectrometry. Also, for minor caffeoyl derivatives and quercetin glycosides, the corresponding sulfo-adducts were observed. Feruloyl and sinapoyl derivatives were not chemically affected by the presence of S. Polyphenol oxidase (PPO) was thought to be responsible for the formation of the sulfo-adducts. This was confirmed by preparing 2'-sulfo-5-O-caffeoyl quinic acid in a model system using 5-CQA, sodium hydrogen sulfite, and PPO. This sulfo-adduct exhibited a small bathochromic shift (λmax 329 nm) as compared to 5-CQA (λmax 325 nm) and a strong hypochromic shift with an extinction coefficient of 9357±395 M(-1) cm(-1) as compared to 18494±196 M(-1) cm(-1), respectively. The results suggest that whenever S is used as an antibrowning agent, the O-quinone formed with PPO reacts with S to produce sulfo-O-diphenol, which does not participate in browning reactions.  相似文献   

Complications and outcome of cats with congenital extrahepatic portosystemic shunts treated with thin film: Thirty-four cases (2008-2017)     

Paula Valiente  Mary Trehy  Rob White  Pieter Nelissen  Jackie Demetriou  Giacomo Stanzani  Benito de la Puerta 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2020,34(1):117-124

  相似文献   

Effects of a short period of drought on changes in tuber volume and specific leaf weight. II. Diurnal changes     

Jadwiga W. Płodowska  Peter H. J. Jongebloed  Pieter A. C. M. Van De Sanden  Paul C. Struik 《Potato Research》1989,32(3):255-266

Summary Single-stemmed potato plants, cv. Bintje, were grown on a nutrient solution under controlled conditions. They were exposed to a short drought stress, or remained untreated. Short-term changes in tuber volume and in specific leaf weight were measured non-destructively. Tubers from control plants increased rapidly in volume during the night and did not grow, or even shrivelled during the day. Tubers of stressed plants did not show a uniform response; some tubers markedly declined in volume during the day. The patterns of volume increase of stressed plants became erratic after the stress, mainly because some plants never fully recovered. Patterns of diurnal fluctuation in tuber volume were similar to diurnal changes in specific leaf weight; tubers within the same stressed plant sometimes reacted differently. In these cases the effects on the diurnal fluctuation partly reflected the long-term effects, reported in an earlier paper.  相似文献   

Context matters: the landscape matrix determines the population genetic structure of temperate forest herbs across Europe     

Naaf  Tobias  Feigs  Jannis Till  Huang  Siyu  Brunet  Jörg  Cousins  Sara A. O.  Decocq  Guillaume  De Frenne  Pieter  Diekmann  Martin  Govaert  Sanne  Hedwall  Per-Ola  Lenoir  Jonathan  Liira  Jaan  Meeussen  Camille  Plue  Jan  Vangansbeke  Pieter  Vanneste  Thomas  Verheyen  Kris  Holzhauer  Stephanie I. J.  Kramp  Katja 《Landscape Ecology》2022,37(5):1365-1384

Landscape Ecology - Plant populations in agricultural landscapes are mostly fragmented and their functional connectivity often depends on seed and pollen dispersal by animals. However, little is...  相似文献   

Cultural ecosystem services in an urban park: understanding bundles,trade-offs,and synergies     

Cheng  Xin  Van Damme  Sylvie  Li  Luyuan  Uyttenhove  Pieter 《Landscape Ecology》2022,37(6):1693-1705

Landscape Ecology - Sets of ecosystem services that occur together across space or time are called ‘bundles’, and the interactions among them can result in synergies or trade-offs....  相似文献   

Symptomatological and histopathological observations on oil palms from Brazil and Ecuador affected by fatal yellowing     

P. Kastelein  W. G. van Slobbe  G. T. N. De Leeuw 《European journal of plant pathology / European Foundation for Plant Pathology》1990,96(2):113-117

Fatal yellowing in oil palms from Brazil and Ecuador is characterized by a chlorosis of the young unfolded leaves and a decay of spear leaves. Contrary to healthy-looking palms, diseased palms do not have roots with soft and white tips.In search for a possible causal agent of fatal yellowing, tissues of leaves, the apical region of stems and root tips of healthy-looking and diseased palms were examined by light microscopy. Fungi and bacteria were frequently, but not always found in necrotic lesions in the leaves. These organisms, however, have never been found outside the lesions or in the vascular tissues of affected palms, nor in the tissues of healthy-looking palms. Tyloses frequently occluded the xylem vessels of affected leaves. In a diseased palm from Ecuador hypertrophic cells were found in the epidermal layer of the pinnae of a spear leaf with water-soaked lesions. In the apical region of the stems and roots of diseased palms, only a few meristematic cells could be detected.Samenvatting Speerrot van oliepalmen in Brazilië en Ecuador wordt gekenmerkt door vergeling van de jongere, geheel geopende bladeren en een rot van de speer. In tegenstelling tot palmen zonder ziekteverschijnselen, hebben aangetaste palmen geen wortels met zachte, witte worteltoppen.Weefsel van bladeren, de apex van de stam en toppen van jonge wortels van gezonduitziende en zieke palmen werden m.b.v. de lichtmicroscoop onderzocht op de aanwezigheid van een eventueel pathogeen. Schimmels en bacteriën werden vaak, doch niet altijd, waargenomen in necrotische lesies op de bladeren, maar nooit buiten lesies of in de vaatbundels van zieke palmen en de weefsels van gezond-uitziende palmen. Vaak verstopten thyllen de houtvaten van aangetaste bladeren. In een speerblad van een zieke palm uit Ecuador werden enige gehypertrofieerde cellen waargenomen in de epidermis van pinnae met waterige lesies. In de top van de stammen en wortels werden slechts enkele meristematische cellen waargenomen.  相似文献   

All you ever wanted to know about pig genetics,but were too busy to look up     

Pieter W. Knap 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2012,129(2):89-91

  相似文献   

Tree bark as a non-timber forest product: The effect of bark collection on population structure and dynamics of Garcinia lucida Vesque     

Nicole Marie Guedje  Pieter A. Zuidema  Heinjo During  Bernard Foahom  Jean Lejoly 《Forest Ecology and Management》2007,240(1-3):1-12

A 2-year demographic field study was carried out on the understorey tree Garcinia lucida in the humid Atlantic forests of South Cameroon. The bark and the seeds of the species are exploited for medicinal purposes and palm wine processing in West and Central Africa. The bark is often removed over almost the entire circumference of the stem, leading to high mortality rates. The goal of the study was to assess the impact of bark harvesting on population structure and dynamics, in order to obtain an indication to what extent the actual harvesting practices can be sustained for longer periods, and to provide information on the future availability of the resource. Comparison of populations that had been subject to different harvest regimes allowed assessment of the effects of G. lucida bark harvesting on population stand structure. In lightly exploited populations, unharvested individuals represented more than the half of the trees (>10 cm DBH), while this was only one-third in heavily exploited stands. The percentage of dead exploited trees (>20 cm DBH) was more than 40 and 70%, for lightly and heavily exploited populations, respectively. This reflects the high intensity of bark harvesting, mainly directed at large trees. For the assessment of bark harvesting on population dynamics, we constructed matrix models for each of the three common bark harvest practices: (1) partial debarking of stem, (2) ring-barking trees and (3) felling trees at approximately 1 m height above ground level to extract bark. For all harvest practices, the asymptotic population growth rates (λ) were not significantly different from 1 indicating that populations were neither growing nor decreasing in size. Nevertheless, model projections showed that the stock of available trees decreased. Under an annual regime of partial debarking of all trees >10 cm DBH, the amount of harvestable trees gradually declined and reached 50% of the initial size after 20 years. For ring-barking and felling trees, the projections showed a sharp drop in the amount of harvestable trees directly after the start of the simulations, and the amount continued to decline below 4% of the initial size under an annual harvest regime. Even after a long time, populations did not recover to their pre-harvest numbers. The stable size of harvested populations predicted by λ values suggest that current harvest practices of bark do not jeopardize the future existence of G. lucida populations. However, as the frequently applied harvest practices of ring-barking and felling strongly reduced the stock in our simulations, commercial bark exploitation cannot be sustained over long periods. Nevertheless, as long as populations can recover from the loss of exploited individuals, by continuous recruitment, there is still prospect for sustained bark extraction.  相似文献   

Overview of on-farm bioremediation systems to reduce the occurrence of point source contamination     

De Wilde T  Spanoghe P  Debaer C  Ryckeboer J  Springael D  Jaeken P 《Pest management science》2007,63(2):111-128

Contamination of ground and surface water puts pressure on the use of pesticides. Pesticide contamination of water can often be linked to point sources rather than to diffuse sources. Examples of such point sources are areas on farms where pesticides are handled and filled into sprayers, and where sprayers are cleaned. To reduce contamination from these point sources, different kinds of bioremediation system are being researched in various member states of the EU. Bioremediation is the use of living organisms, primarily microorganisms, to degrade the environmental contaminants into less toxic forms. The systems available for biocleaning of pesticides vary according to their shape and design. Up till now, three systems have been extensively described and reported: the biobed, the Phytobac and the biofilter. Most of these constructions are excavations or different sizes of container filled with biological material. Typical overall clean-up efficiency exceeds 95%, realising even more than 99% in many cases. This paper provides an overview of the state of the art of these bioremediation systems and discusses their construction, efficiency and drawbacks.  相似文献