373 research outputs found

    Agromere: how to integrate urban agriculture in the development of the Dutch city of Almere?

    Get PDF
    Urban agriculture produces green city areas with as an extra dimension providing food, energy, care, education or recreation for the civilians. And thus it can contribute to a more sustainable and liveable cities. The objective of the project Agromere is to create a process which will lead to a new residential quarter where agriculture is fully integrated in city live. Agromere is situated in the fast growing city of Almere, the Netherlands. In a combined stakeholder and design process a township is designed which integrates living (5,000 inhabitants) with urban agriculture on 250 ha. During this process an enthusiastic network of stakeholders has been established which developed innovating and unique ideas on urban farming. The potential for organic farming in the city is high because of its emphasis on animal welfare and consumer relations

    The scientific career of the zoologist Max Wilhelm Carl Weber (1852—1937)

    Get PDF
    It is shown that the pinnacle of Max Weber’s scientific career was the organization and leadership of the Siboga Expedition to the former Netherlands East Indies (now Indonesia)in the years 1899—1900. Before that time, as Professor of both General and Special Zoology at the University of Amsterdam, he had devoted his research mainly to the anatomy of mammals, which resulted in the fundamental reference work Die Säugetiere published in first edition in 1904. Just before his departure with the Siboga Expedition Weber was appointed Extraordinary Professor of Special Zoology in Amsterdam. This gave him more time to edit the results of the Siboga Expedition and for taxonomic studies, especially on the fishes of the Indo- Australian Archipelago. Nevertheless he kept a keen interest in generalzoology, which resulted in his extensive contribution to the modern textbook Lehrbuch der Biologiefür Hochschulen co-authored by Moritz Nussbaum and Georg Karsten, published in first edition in 1911. Weber retired in 1921 and by the time he died in 1937 about 95% of the scientific results of the Siboga Expedition had been published - an outstanding achievement

    Assessment of the attraction flow in a fish passage

    Get PDF
    An attraction flow can be used to increase the effectivity of a fish passage. In 2004 a fish passage with a perpendicular attraction flow was built at Oudenaarde (Belgium) on the Upper Scheldt river. The design of the passage was based on scale model tests. In order to evaluate the hydraulic effectivity of the attraction flow, field measurements and new scale model tests are done. Velocities in the attraction flow and the fish passage entrance are assessed quantitatively and data of the scale model tests (1/15) are compared with the field measurements. The measured reach of the attraction flow seems to differ from results of the original scale model tests due to design modifications of the fish passage entrance. Results of the new scale model tests compare well with the data from the field measurements. Based on the results, a re-examination of the basic design rules for the attraction flow and fish pass entrances seems imperativ

    Late-Time Correlators and Complex Geodesics in de Sitter Space

    Full text link
    We study two-point correlation functions of a massive free scalar field in de Sitter space using the heat kernel formalism. Focusing on two operators in conjugate static patches we derive a geodesic approximation to the two-point correlator valid for large mass and at late times. This expression involves a sum over two complex conjugate geodesics that correctly reproduces the large-mass, late-time limit of the exact two-point function in the Bunch-Davies vacuum. The exponential decay of the late-time correlator is associated to the timelike part of the complex geodesics. We emphasize that the late-time exponential decay is in tension with the finite maximal entropy of empty de Sitter space, and we briefly discuss how non-perturbative corrections might resolve this paradox.Comment: 18 pages, 8 figures. v2: 19 pages + 2 pages appendices, 11 figures. Matches published versio

    Integrating morphological and physiological responses of tomato plants to light quality to the crop level by 3D modeling

    Get PDF
    Next to its intensity, the spectral composition of light is one of the most important factors affecting plant growth and morphology. The introduction of light emitting diodes (LEDs) offers perspectives to design optimal light spectra for plant production systems. However, knowledge on the effects of light quality on physiological plant processes is still limited. The aim of this study is to determine the effects of six light qualities on growth and plant architecture of young tomato plants, and to upscale these effects to the crop level using a multispectral, functional-structural plant model. Young tomato plants were grown under 210 μmol m-2 s-1 blue, green, amber, red, white or red/blue (92%/8%) LED light with a low intensity of sunlight as background. Plants grown under blue light were shorter and developed smaller leaves which were obliquely oriented upward. Leaves grown under blue light contained the highest levels of light harvesting pigments, but when exposed to blue light only, they had the lowest rate of leaf photosynthesis. However, when exposed to white light these leaves had the highest rate of photosynthesis. Under green light, tomato plants were taller and leaves were nearly horizontally oriented, with a high specific leaf area. The open plant structure combined with a high light transmission and reflection at the leaf level allowed green light to penetrate deeper into the canopy. Plants grown under red, amber and white light were comparable with respect to height, leaf area and biomass production. The 3D model simulations indicated that the observed changes in plant architecture had a significant impact on light absorbance at the leaf and crop level. The combination of plant architecture and spectrum dependent photosynthesis was found to result in the highest rate of crop photosynthesis under red light in plants initially grown under green light. These results suggest that dynamic light spectra may offer perspectives to increase growth and production in high value production systems such as greenhouse horticulture and vertical farming.</p

    Social behavior assessment in cognitively impaired older adults using a passive and remote smartphone application

    Get PDF
    BACKGROUND: In Alzheimer's Disease (AD), loss of social interactions has a major impact on well-being. Therefore, AD patients would benefit from early detection of symptoms of social withdrawal. Current measurement techniques such as questionnaires are subjective and rely on recall, in contradiction to smartphone applications, which measure social behavior passively and objectively. Here, we examine social interactions through passive remote monitoring with the smartphone application BEHAPP in cognitively impaired participants. This study aims to investigate (1) the association between demographic characteristics and BEHAPP outcome variables in cognitively normal (CN) older adults, (2) if social behavior as measured using the passive smartphone app BEHAPP is impaired in cognitively impaired (CI) participants compared to subjects with subjective cognitive decline (SCD), and CN older adults. In addition, we explored in a subset of individuals the association between BEHAPP outcomes and neuropsychiatric symptoms. METHOD: CN (n=209), SCD (n=55) and CI (n=22) participants, older than 45 years, installed the BEHAPP app on their own Android smartphone for 7-42 days. CI participants had a clinical diagnosis of mild cognitive impairment or AD-type dementia. The app continuously measured communication events, application usage and location. Neuropsychiatric Inventory (NPI) total scores were available from 20 SCD and 22 CI participants. RESULT: We found that older cognitively healthy participants called less frequently and made less use of apps. No sex effects were found. Linear models corrected for age, sex and education showed that compared to the CN and SCD groups, CI participants called less unique contacts and contacted the same contacts relatively more often (Figure 1). They also made less use of apps, visited less unique places and traveled less far from home. Higher total NPI scores were associated with more unique stay points and further travelling. Similar behavior patterns were found when correcting for multiple comparisons. CONCLUSION: Cognitively impaired individuals show reduced social activity, as measured by the smartphone application BEHAPP. Neuropsychiatric symptoms seemed only marginally associated with social behavior as measured with BEHAPP. This research shows that a passive and remote smartphone application is able to objectively and passively measure altered social behavior in a cognitively impaired population
    • …
    corecore