58 research outputs found

    Life cycle assessment of tomato production for different production strategies in Norway

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    The availability of fresh vegetables grown in greenhouses under controlled conditions throughout the year has given rise to concerns about their impact on the environment. In high latitude countries such as Norway, greenhouse vegetable production requires large amounts of energy for heat and light, especially during the winter. The use of renewable energy such as hydroelectricity and its effect on the environment has not been well documented. Neither has the effect of different production strategies on the environment been studied to a large extent. We conducted a life cycle assessment (LCA) of greenhouse tomato production for mid-March to mid-October (seasonal production), 20th January to 20th November (extended seasonal) production, and year-round production including the processes from raw material extraction to farm gate. Three production seasons and six greenhouse designs were included, at one location in southwestern and one in northern Norway. The SimaPro software was used to calculate the environmental impact. Across the three production seasons, the lowest global warming (GW) potential (600 g CO2-eq per 1 kg tomatoes) was observed during year-round production in southwestern Norway for the design NDSFMLLED + LED, while the highest GW potential (3100 g CO2-eq per 1 kg tomatoes) was observed during seasonal production in northern Norway for the design NS. The choice of artificial lighting (HPS (High Pressure Sodium) or LED (Light Emitting Diodes)), heating system and the production season was found to have had a considerable effect on the environmental impact. Moreover, there was a significant reduction in most of the impact categories including GW potential, terrestrial acidification, and fossil resource scarcity from seasonal to year-round production. Overall, year-round production in southwestern Norway had the lowest environmental impact of the evaluated production types. Heating of the greenhouse using natural gas and electricity was the biggest contributor to most of the impact categories. The use of an electric heat pump and LED lights during extended seasonal and year-round production both decreased the environmental impact. However, while replacing natural gas with electricity resulted in decreased GW potential, it increased the ecotoxicity potential.publishedVersio

    Artificial top-light is more efficient for tomato production than inter-light

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    Studies of whole-plant responses of tomato to light environments are limited and cannot be extrapolated from observations of seedlings or short-term crops in growth chambers. Effects of artificial light sources like high pressure sodium (HPS) and light emitting diodes (LED) are mainly studied as supplement to sunlight in greenhouses. Since natural sunlight is almost neglectable in Norway during wintertime, we could study effects of different types of artificial light on crop growth and production in tomato. The goal of this experiment was to quantify the effects of artificial HPS top-light, installed at the top of the canopy, and LED inter-light, installed between plant rows, on fresh and dry matter production and fruit quality of greenhouse tomatoes under controlled and documented conditions. Our aim was to optimize yield under different light conditions, while avoiding an unfavourable source-sink balance. Tomato plants were grown under HPS top light with an installed capacity of 161, 242 and 272 W m‚ąí2 combined with LED inter-light with an installed capacity of 0, 60 or 120 W m‚ąí2. We used stem diameter as a trait to regulate air temperature in different light treatments in order to retain plant vigour. Results show that both HPS top light and LED inter-light increased tomato yield. However, the positive effect of supplemental LED inter-light decreased at higher amounts of HPS top light. Under the conditions in this experiment, with neglectable incoming solar radiation, an installed amount of 242 Watt m-2 HPS top light and a daily light integral (DLI) of 30 mol m-2 day-1 resulted in best light use efficiency (in gram fresh tomato per mol). Addition of LED inter-light to HPS top light reduced light use efficiency. Results show that winter production using artificial light in Norway is more energy efficient compared to production under sunlight in southern countries. Results can be used for modelling purposes.acceptedVersio

    Organic Waste-Based Fertilizer in Hydroponics Increases Tomato Fruit Size but Reduces Fruit Quality

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    In regions with intensive agricultural production, large amounts of organic waste are produced by livestock animals. Liquid digestate from manure-based biogas production could potentially serve as fertilizer if integrated with closed horticultural irrigation systems. The aim of this experiment was to investigate how fertilizer based on liquid biogas by-products of pig manure digestion can affect the growth and production of tomato plants. Integration of a nitrification bioreactor presumes a significantly lower concentration of nutrient solutions and a higher level of oxygenation than classical mineral cultivation. Therefore, additional controls were included. We compared plant growth and fruit quality traits of tomato plants grown in a hydroponic solution with organic fertilizer with two levels of mineral fertilizer. The tomatoes grown with organic waste-based liquid fertilizer showed reduced growth rates but increased mean fruit size, resulting in no significant change in total yield compared with high-mineral cultivation. The growth rate was similarly reduced in plants cultivated with low-mineral fertilizer. Plants cultivated with organic waste-based fertilizer had high Cl‚ąí concentration in xylem sap, leaves, and, ultimately, fruits. The leaves of plants cultivated with organic waste-based fertilizer contained higher concentrations of starch and soluble carbohydrate and low concentrations of phosphorous (P) and sulfur (S). The plants grown with organic waste-based or low-mineral medium showed significantly poorer fruit quality than the plants cultivated with the high-mineral solution. The low-mineral treatment increased xylem sap contribution to fruit weight because of higher root power. The organic waste-based fertilization did not change the root power but increased fruit size. In conclusion, organic waste-based cultivation is a possible solution for sustainable plant production in greenhouses. However, additional adjustment of nutrient supply is required to improve fruit quality

    Implementation of outpatient schema therapy for borderline personality disorder: study design

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    ABSTRACT: BACKGROUND: Schema Therapy (ST) is an integrative psychotherapy based upon a cognitive schema model which aims at identifying and changing dysfunctional schemas and modes through cognitive, experiential and behavioral pathways. It is specifically developed for patients with personality disorders. Its effectiveness and efficiency have been demonstrated in a few randomized controlled trials, but ST has not been evaluated in regular mental healthcare settings. This paper describes the study protocol of a multisite randomized 2-group design, aimed at evaluating the implementation of outpatient schema therapy for patients with borderline personality disorder (BPD) in regular mental healthcare and at determining the added value of therapist telephone availability outside office hours in case of crisis. METHODS/DESIGN: Patient outcome measures will be assessed with a semi-structured interview and self-report measures on BPD, therapeutic alliance, quality of life, costs and general psychopathology at baseline, 6, 12, 18 and 36 months. Intention-to-treat analyses will be executed with survival analysis for dichotomous variables, and one-sample t-tests and ANCOVAs for continuous variables with baseline as covariate and condition as between group factor. All tests will be two-tailed with a significance level of 5%. DISCUSSION: The study will provide an answer to the question whether ST can be effectively implemented and whether phone support by the therapist has an additional value. TRIAL REGISTRATION: The Dutch Cochrane Center, NTR (TC = 1781

    Detection and localization of early- and late-stage cancers using platelet RNA

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    Cancer patients benefit from early tumor detection since treatment outcomes are more favorable for less advanced cancers. Platelets are involved in cancer progression and are considered a promising biosource for cancer detection, as they alter their RNA content upon local and systemic cues. We show that tumor-educated platelet (TEP) RNA-based blood tests enable the detection of 18 cancer types. With 99% specificity in asymptomatic controls, thromboSeq correctly detected the presence of cancer in two-thirds of 1,096 blood samples from stage I‚ÄďIV cancer patients and in half of 352 stage I‚ÄďIII tumors. Symptomatic controls, including inflammatory and cardiovascular diseases, and benign tumors had increased false-positive test results with an average specificity of 78%. Moreover, thromboSeq determined the tumor site of origin in five different tumor types correctly in over 80% of the cancer patients. These results highlight the potential properties of TEP-derived RNA panels to supplement current approaches for blood-based cancer screening

    Exploring the opportunities for building a rooftop greenhouse . Case study from Bergen, Norway

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    Building greenhouses on rooftops in cities has several advantages. Shorter distance to consumers gives fresher products and less financial expenses and pollution from transport and storage. This is particularly important in cities located far away from where the food is produced. Rooftop greenhouses in cities can also give the urban population the opportunity to learn more about how food is produced. Building greenhouses on roofs instead of on the ground saves space that can instead be used for agriculture, green space or other types of housing. A rooftop greenhouse integrated with the building below can use excess heat from this building, which saves energy. An increasing number of rooftop greenhouses have been built in cities around the world. Some of these greenhouses are commercial and sell what they produce through supermarkets, restaurants, their own shops or food box schemes. Some rooftop greenhouses are also built for universities and schools, and are used for educational purposes. Most of these greenhouses use hydroponic systems for irrigation and fertilization of the plants. But building a rooftop greenhouse has certain challenges. If the greenhouse is to be built on an existing building it might not have the carrying capacity for an extra floor. This requires strengthening of the building, which can be expensive. Other factors which will increase the costs compared to a greenhouse on ground is building access to the greenhouse and integrating it with the building below for exchange of heat and air. It can also be difficult to get permission to build a greenhouse on a rooftop in a city centre for aesthetical reasons and because regulations only permit a certain number of floors on buildings in the area. Getting an exemption from these rules can be a challenge. In addition, it might be necessary to pay rent for the area that the greenhouse is built on. To compensate for these higher costs a rooftop greenhouse can generate extra income from a higher willingness to pay among consumers, for instance because it provides fresher products, or because the greenhouse is seen as a local, environmentally friendly concept generating employment in the neighbourhood. Other activities such as guided tours and education can help make the greenhouse more than just a commercial producer. Direct sales to consumers through its own shop or restaurant or a food box scheme can also increase income, as a larger share of the final price goes to the producer. In this project three researchers have collaborated with a group consisting of architects, real estate companies, gardeners, chefs and representatives for local authorities, as well as the Bergen City Farmer. Preliminary results have been presented and discussed throughout the project period. A case study analysis has been developed based on the building ‚ÄúBontelabo‚ÄĚ in the centre of Bergen, looking at costs and market opportunities. The case study includes architect designed drawings. The project shows that building a rooftop greenhouse involves extra investment costs compared with a greenhouse on the ground. But an increased focus on the social and environmental advantages of rooftop greenhouses can give both increased opportunities for investment support, for example from public authorities, and higher willingness to pay among consumers for the greenhouse products. This may increase opportunities for profitability. With an increased focus on climate change and extreme weather events we can except increased appreciation of the advantages that rooftop greenhouses have for the environment, and for the possibilities for cities to produce their own food.publishedVersio

    Vurdering av avrenningsvann i veksthusgr√łnnsaker

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    Dagens produksjonsmetode av veksthusgr√łnnsaker gir betydelig utslipp av n√¶ringsstoffer. Det er en situasjon som er u√łnsket og kan f√łre til forurensing av n√¶rmilj√łet, bruk av for mye n√¶ringsstoffer og √łkonomisk tap for produsenter. Registreringer viser at avrenningsprosenter kan variere mellom 30 og 40 % i tomat og agurk. Tapet av n√¶ringsstoffer ble estimert. Det ble p√•vist at det er mulig √• begrense mengde avrenningsvann ved √• tilpasse vanningsteknikk. Men bruk av denne vanningsteknikken forutsetter at vanntilf√łrselen er 100% n√łyaktig. Avvik vil ha store konsekvenser for avling og/eller kvalitet av produktene og dermed for √łkonomien for den enkelte produsent, og er dermed enda ikke forsvarlig. Resirkulering av avrenningsvann er teknisk mulig. Det vil redusere avrenningen med tiln√¶rmet 100%. Desinfeksjon av avrenningsvann er helt n√łdvendige for √• unng√• spredning av sykdommer. Det er god erfaring med gode teknikker fra utlandet, og teknikkene er beskrevet i rapporten. Resirkulering vil kreve en investering i bl.a. oppsamlingstanker, rensesystemer og en ny gj√łdselblander. Denne investeringen vil √łke produksjonskostnader for gartnerier med et gjennomsnittsareal p√• 1000-3000 m2 med ca 25 %. Besparelsen av utgifter for gj√łdsling og vann er estimert p√• 0,10 til 0,15 nok/kg. Rapporten konkluderer at det er pr i dag for de fleste bedrifter ul√łnnsom √• investere i et slikt vanningssystem

    Supplemental Light-Emitting Diode Inter-Lighting Increases Tomato Fruit Growth Through Enhanced Photosynthetic Light Use Efficiency and Modulated Root Activity

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    We investigated the effect of supplemental LED inter-lighting (80% red, 20% blue; 70 W m‚ąí2; light period 04:00‚Äď22:00) on the productivity and physiological traits of tomato plants (Flavance F1) grown in an industrial greenhouse with high pressure sodium (HPS) lamps (235 W m‚ąí2, 420 ¬Ķmol m‚ąí2 s‚ąí1 at canopy). Physiological trait measurements included diurnal photosynthesis and fruit relative growth rates, fruit weight at specific positions in the truss, root pressure, xylem sap hormone and ion compositions, and fruit quality. In the control treatment with HPS lamps alone, the ratio of far-red to red light (FR:R) was 1.2 at the top of the canopy and increased to 5.4 at the bottom. The supplemental LED inter-lighting decreased the FR:R ratio at the middle and low positions in the canopy and was associated with greener leaves and higher photosynthetic light use efficiency (PLUE) in the leaves in the lower canopy. The use of LED inter-lighting increased the biomass and yield by increasing the fruit weight and enhancing plant growth. The PLUE of plants receiving supplemental LED light decreased at the end of the light period, indicating that photosynthesis of the supplemented plants at the end of the day might be limited by sink capacity. The supplemental LED lighting increased the size of fruits in the middle and distal positions of the truss, resulting in a more even size for each fruit in the truss. Diurnal analysis of fruit growth showed that fruits grew more quickly during the night on the plants receiving LED light than on unsupplemented control plants. This faster fruit growth during the night was related to an increased root pressure. The LED treatment also increased the xylem levels of the phytohormone jasmonate. Supplemental LED inter-lighting increased tomato fruit weight without affecting the total soluble solid contents in fruits by increasing the total assimilates available for fruit growth and by enhancing root activity through an increase in root pressure and water supply to support fruit growth during the night.publishedVersio

    Nitrogen Deficiency and Synergism between Continuous Light and Root Ammonium Supply Modulate Distinct but Overlapping Patterns of Phytohormone Composition in Xylem Sap of Tomato Plants

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    Continuous light (CL) or a predominant nitrogen supply as ammonium (NH4+) can induce leaf chlorosis and inhibit plant growth. The similarity in injuries caused by CL and NH4+ suggests involvement of overlapping mechanisms in plant responses to these conditions; however, these mechanisms are poorly understood. We addressed this topic by conducting full factorial experiments with tomato plants to investigate the effects of NO3‚ąí or NH4+ supply under diurnal light (DL) or CL. We used plants at ages of 26 and 15 days after sowing to initiate the treatments, and we modulated the intensity of the stress induced by CL and an exclusive NH4+ supply from mild to strong. Under DL, we also studied the effect of nitrogen (N) deficiency and mixed application of NO3‚ąí and NH4+. Under strong stress, CL and exclusive NH4+ supply synergistically inhibited plant growth and reduced chlorophyll content. Under mild stress, when no synergetic effect between CL and NH4+ was apparent on plant growth and chlorophyll content, we found a synergetic effect of CL and NH4+ on the accumulation of several plant stress hormones, with an especially strong effect for jasmonic acid (JA) and 1-aminocyclopropane-1-carboxylic acid (ACC), the immediate precursor of ethylene, in xylem sap. This modulation of the hormonal composition suggests a potential role for these plant hormones in plant growth responses to the combined application of CL and NH4+. No synergetic effect was observed between CL and NH4+ for the accumulation of soluble carbohydrates or of mineral ions, indicating that these plant traits are less sensitive than the modulation of hormonal composition in xylem sap to the combined CL and NH4+ application. Under diurnal light, NH4+ did not affect the hormonal composition of xylem sap; however, N deficiency strongly increased the concentrations of phaseic acid (PA), JA, and salicylic acid (SA), indicating that decreased N concentration rather than the presence of NO3‚ąí or NH4+ in the nutrient solution drives the hormone composition of the xylem sap. In conclusion, N deficiency or a combined application of CL and NH4+ induced the accumulation of JA in xylem sap. This accumulation, in combination with other plant hormones, defines the specific plant response to stress conditions.publishedVersio
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