182 research outputs found

    William James and the development of phenomenological psychology in Europe

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    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively

    A meta-analysis of plant tissue O2 dynamics

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    Adequate tissue O2 supply is crucial for plant function. We aimed to identify the environmental conditions and plant characteristics that affect plant tissue O2 status. We extracted data and performed meta-analysis on >1500 published tissue O2 measurements from 112 species. Tissue O2 status ranged from anoxic conditions in roots to >53kPa in submerged, photosynthesising shoots. Using information-theoretic model selection, we identified 'submergence', 'light', 'tissue type' as well as 'lightĂ—submergence' interaction as significant drivers of tissue O2 status. Median O2 status were especially low (<50% of atmospheric equilibrium) in belowground rhizomes, potato (Solanum tuberosum) tubers and root nodules. Mean shoot and root O2 were ~25% higher in light than in dark when shoots had atmospheric contact. However, light showed a significant interaction with submergence on plant O2, with a submergence-induced 44% increase in light, compared with a 42% decline in dark, relative to plants with atmospheric contact. During submergence, ambient water column O2 and shoot tissue O2 correlated stronger in darkness than in light conditions. Although use of miniaturised Clark-type O2 electrodes has enhanced understanding of plant O2 dynamics, application of non-invasive methods in plants is still lacking behind its widespread use in mammalian tissues

    Phänomenologie und Experiment in der Psychologie

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    Nach der Diskussion einiger Vorurteile, die das Verhältnis von Phänomenologie und Experiment in der Psychologie belasten, werden ihr gemeinsamer historischer Ausgangspunkt und die gegenseitige methodische Beeinflussung aufgezeigt. Aus dem phänomenologischen Grundbegriff "Intentionalität" wird die methodische Unverzichtbarkeit von Deskription und lebensweltlicher Sinnrekonstitution in Ergänzung zur Variation durch das Experiment dargelegt. Es wird für eine Integration von phänomenologischer und experimenteller Arbeit in der Psychologie unter dem Primat der Phänomene selbst plädiert

    Responses of key root traits in the genus Oryza to soil flooding mimicked by stagnant, deoxygenated nutrient solution

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    Excess water can induce flooding stress resulting in yield loss, even in wetland crops such as rice (Oryza). However, traits from species of wild Oryza have already been used to improve tolerance to abiotic stress in cultivated rice. This study aimed to establish root responses to sudden soil flooding among eight wild relatives of rice with different habitat preferences benchmarked against three genotypes of O. sativa. Plants were raised hydroponically, mimicking drained or flooded soils, to assess the plasticity of adventitious roots. Traits included were apparent permeance (P-A) to O-2 of the outer part of the roots, radial water loss, tissue porosity, apoplastic barriers in the exodermis, and root anatomical traits. These were analysed using a plasticity index and hierarchical clustering based on principal component analysis. For example, O. brachyantha, a wetland species, possessed very low tissue porosity compared with other wetland species, whereas dryland species O. latifolia and O. granulata exhibited significantly lower plasticity compared with wetland species and clustered in their own group. Most species clustered according to growing conditions based on P-A, radial water loss, root porosity, and key anatomical traits, indicating strong anatomical and physiological responses to sudden soil flooding.Soil flooding resulted in strong acclimation in key root traits for three cultivars and six wild species of rice, while two dryland species showed little plasticity in root traits

    Brane/flux annihilation transitions and nonperturbative moduli stabilization

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    By extending the calculation of Kahler moduli stabilization to account for an embiggened antibrane, we reevaluate brane/flux annihilation in a warped throat with one stabilized Kahler modulus. We find that depending on the relative size of various fluxes three things can occur: the decay process proceeds unhindered, the anti-D3-branes are forbidden to decay classically, or the entire space decompactifies. Additionally, we show that the Kahler modulus receives a contribution from the collective 3-brane tension. This allows for a significant change in compactified volume during the transition and possibly mitigates some fine tuning otherwise required to achieve large volume.Comment: 25 pages, 6 figures, LaTeX. v2: references adde

    Betriebliche Bewirtschaftungsindikatoren für Biodiversität im Ökologischen Landbau und in extensiven Anbausystemen in Europa

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    Farming practices are the key to maintaining and restoring farmland biodiversity. Selected farm management indicators, regarded as scientifically sound, practicable and attractive to stakeholders, were tested against species indicators in various farm types in 12 case studies across Europe. A set of eight farm management indicators is recommended, reflecting the pressure on biodiversity by farm management via energy and nutrient input, mechanical operations, pesticide use and livestock

    Inducible Defenses with a "Twist": Daphnia barbata Abandons Bilateral Symmetry in Response to an Ancient Predator

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    Predation is one of the most important drivers of natural selection. In consequence a huge variety of anti-predator defenses have evolved in prey species. Under unpredictable and temporally variable predation pressure, the evolution of phenotypically plastic defensive traits is favored. These "inducible defenses", range from changes in behavior, life history, physiology to morphology and can be found in almost all taxa from bacteria to vertebrates. An important group of model organisms in ecological, evolutionary and environmental research, water fleas of the genus Daphnia (Crustacea: Cladocera), are well known for their ability to respond to predators with an enormous variety of inducible morphological defenses. Here we report on the "twist", a body torsion, as a so far unrecognized inducible morphological defense in Daphnia, expressed by Daphnia barbata exposed to the predatory tadpole shrimp Triops cancriformis. This defense is realized by a twisted carapace with the helmet and the tail spine deviating from the body axis into opposing directions, resulting in a complete abolishment of bilateral symmetry. The twisted morphotype should considerably interfere with the feeding apparatus of the predator, contributing to the effectiveness of the array of defensive traits in D. barbata. As such this study does not only describe a completely novel inducible defense in the genus Daphnia but also presents the first report of a free living Bilateria to flexibly respond to predation risk by abandoning bilateral symmetry

    Flood-tolerant rice for enhanced production and livelihood of smallholder farmers of Africa

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    Climate change has intensified food security challenges, especially in Africa, where a significant portion of produce is reliant on smallholder farmers in rainfed conditions. Prolonged flooding and droughts, driven by erratic weather patterns, have significantly elevated the risk of food scarcity. Floods, in particular, have been responsible for severe crop losses, raising concerns about increasing import costs if this issue is not mitigated. Africa is actively working to mitigate the impacts of flooding and enhance food security, although progress has been gradual. Developing flood-resilient varieties is a promising strategy to address this challenge. We explored various flood types common in the region and observed a scarcity of research on flood-resilient varieties, particularly those adapted for anaerobic germination and stagnant flooding. Conversely, varieties bred for flash flooding, such as FARO 66 and FARO 67, have seen limited distribution, primarily confined to a few West African countries, falling short of the intended impact. In contrast, deepwater tolerance research dates back to the early 1900s, but commercialization of the varieties remains limited, with scarce information regarding their cultivation, coverage, and performance. Newly developed varieties, such as Kolondieba 2 and Kadia 24, have received less attention, leaving many farmers dependent on locally adapted cultivars specific to particular areas. Remarkably, despite the limited information, both released and local stress-tolerant cultivars exhibit substantial survival rates and yield advantages. For instance, FARO 66 and FARO 67 have demonstrated 1–3 t/ha yield advantages over recurrent parents under flooding stress. Nonetheless, further efforts are required to address various forms of flooding. To this end, AfricaRice collaborates with National Rice Development Strategies, IRRI, and other partners to promote research and development. While improved flood-tolerant varieties remain limited in scope across Africa, the financial gains for farmers are significant when compared to susceptible cultivars. As the continent’s population continues to grow rapidly, there is untapped potential in African germplasms, making ongoing research and breeding strategies essential. Therefore, this review highlights the importance of intensifying efforts in screening and identifying flood-tolerant rice. Furthermore, it underscores the value of utilizing traditional flood-resilient cultivars in breeding to enhance the productivity of widely distributed and cultivated varieties
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