550 research outputs found

    A Guide to Human Zinc Absorption: General Overview and Recent Advances of In Vitro Intestinal Models

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    Zinc absorption in the small intestine is one of the main mechanisms regulating the systemic homeostasis of this essential trace element. This review summarizes the key aspects of human zinc homeostasis and distribution. In particular, current knowledge on human intestinal zinc absorption and the influence of diet-derived factors on bioaccessibility and bioavailability as well as intrinsic luminal and basolateral factors with an impact on zinc uptake are discussed. Their investigation is increasingly performed using in vitro cellular intestinal models, which are continually being refined and keep gaining importance for studying zinc uptake and transport via the human intestinal epithelium. The vast majority of these models is based on the human intestinal cell line Caco-2 in combination with other relevant components of the intestinal epithelium, such as mucin-secreting goblet cells and in vitro digestion models, and applying improved compositions of apical and basolateral media to mimic the in vivo situation as closely as possible. Particular emphasis is placed on summarizing previous applications as well as key results of these models, comparing their results to data obtained in humans, and discussing their advantages and limitations.DFG, 316442145, FOR 2558: Interaktionen von essenziellen Spurenelementen in gesunden und erkrankten älteren Menschen (TraceAge)DFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische Universität Berli

    Lawns in Cities: From a Globalised Urban Green Space Phenomenon to Sustainable Nature-Based Solutions

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    This opinion paper discusses urban lawns, the most common part of open green spaces and urban green infrastructures. It highlights both the ecosystem services and also disservices provided by urban lawns based on the authors’ experience of working within interdisciplinary research projects on lawns in different cities of Europe (Germany, Sweden and Russia), New Zealand (Christchurch), USA (Syracuse, NY) and Australia (Perth). It complements this experience with a detailed literature review based on the most recent studies of different biophysical, social, planning and design aspects of lawns. We also used an international workshop as an important part of the research methodology. We argue that although lawns of Europe and the United States of America are now relatively well studied, other parts of the world still underestimate the importance of researching lawns as a complex ecological and social phenomenon. One of the core objectives of this paper is to share a paradigm of nature-based solutions in the context of lawns, which can be an important step towards finding resilient sustainable alternatives for urban green spaces in the time of growing urbanisation, increased urban land use competition, various user demands and related societal challenges of the urban environment. We hypothesise that these solutions may be found in urban ecosystems and various local native plant communities that are rich in species and able to withstand harsh conditions such as heavy trampling and droughts. To support the theoretical hypothesis of the relevance of nature-based solutions for lawns we also suggest and discuss the concept of two natures—different approaches to the vision of urban nature, including the understanding and appreciation of lawns. This will help to increase the awareness of existing local ecological approaches as well as an importance of introducing innovative landscape architecture practices. This article suggests that there is a potential for future transdisciplinary international research that might aid our understanding of lawns in different climatic and socio-cultural conditions as well as develop locally adapted (to environmental conditions, social needs and management policies) and accepted nature-based solutions.Peer Reviewe

    A simplified strategy to package foreign proteins into baculovirus occlusion bodies without engineering the viral genome

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    Polyhedron envelope protein (PEP) is the major component of the calyx that surrounds the baculovirus occlusion body (OB). PEP has been associated with the stabilization and resistance of polyhedra in the environment. Due to the abundant levels of PEP in OBs, we decided to use this protein as a fusion partner to redirect foreign proteins to baculovirus polyhedra. In this study we developed a strategy that involves the generation of a monoclonal transformed insect cell line expressing a protein of interest fused to the the Anticarsia gemmatalis multiple nucleopolyhedrovirus (AgMNPV) N-terminus of PEP that enables the packaging of foreign proteins into the OBs without generating a recombinant baculovirus. This proved to be an efficient platform that could be exploited to improve wild type baculovirus for their use as bioinsecticides without facing the concerns of releasing genetically modified DNA to the environment and bypassing the associated regulatory issues. We demonstrated, using immunological, proteomic and microscopy techniques, that the envelope of AgMNPV OBs can effectively trap chimeric proteins in an infected insect cell line expressing AgMNPV PEP fused to the enhanced green fluorescent protein (eGFP). Furthermore, packaging of chimeric PEP also took place with heterologous OBs such as those of Autographa californica multiple nucleopolyhedrovirus (AcMNPV), another group I alphabaculovirus.Fil: Fabre, Maria Laura. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular; ArgentinaFil: Masson, Tomas. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular; ArgentinaFil: Haase, Santiago. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular; ArgentinaFil: Ferrelli, Maria Leticia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular; ArgentinaFil: Romanowski, Victor. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular; Argentin

    On the proper reconstruction of complex dynamical systems spoilt by strong measurement noise

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    This article reports on a new approach to properly analyze time series of dynamical systems which are spoilt by the simultaneous presence of dynamical noise and measurement noise. It is shown that even strong external measurement noise as well as dynamical noise which is an intrinsic part of the dynamical process can be quantified correctly, solely on the basis of measured times series and proper data analysis. Finally real world data sets are presented pointing out the relevance of the new approach

    Macroclimate and local hydrological regime as drivers of fen vegetation patterns in Tierra del Fuego (Argentina)

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    In southern South America, a sharp macroclimatic gradient is found, triggered by the Pacific oceanic influence through the Andes. Mires are substantial landscape units along the gradient, where they play varying roles through the area and include varying plant communities. In this study, we analysed the relationship between vegetation and main abiotic factors in the minerotrophic mires (fens) at two different scales. We chose three fens in Isla Grande from Cordillera and Magellanic Steppe zones and their ecotone. There we characterized the distinct habitats by means of monitoring the water table fluctuations, the peat and the groundwater chemistry, and the vascular plant species composition. The main floristic patterns were revealed by means of classification and ordination of 75 vegetation plots. Thus, we classified the relevés through multivariate analyses into six plant community types, two of which found in each fen. Behind the floristic distinctiveness of each site and each community type, structural vegetation descriptors such as species richness were similar. Overall, water table variables and groundwater chemistry showed the most important environmental differences between fens. Our data point that the main environmental force driving vegetation patterns was the macroclimatic gradient, which shapes the regional floristic pools. This gradient would be also responsible for modifying the local conditions of the fen habitats, mostly in the form of broadening the hydrological conditions within the fens of the Steppe. At each fen, the hydrological regime is the main factor in the distribution of vascular plants, particularly through the varying water table depths

    Entwicklung eines stickstoffbasierten Ertragsprognosemodells zur Optimierung des Ă–kologischen Kartoffelbaus

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    Potatoes are one of the most important crops in organic farming with respect to farmers’ income. Yields are often strongly influenced by regional and yearly diffe-rences. Despite the availability of detailed knowledge, it is only now that a crop growth model has been generated which allows for the estimation and prediction of potato yield under organic conditions. The aim of our study was to produce a highly elaborate prediction model based on the utilization and speed of nitrogen uptake as they relate to the yield dynamics of tubers and canopy in combination with late blight dynamics. Therefore, from 2005 to 2014, these parameters were assessed in up to 18 varieties of potatoes comprised of differing maturity groups. The data were ana-lyzed in R using similar algorithms to the Grofit package. Our distinct model included updated mathematical functions to estimate the yield development in organic potato-es. Finally, we demonstrate that at a relatively early time in the season it is possible to estimate the yield of potatoes of various varieties and maturity groups

    Brennpunkt Wavelets

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    Im multimedialen Zeitalter müssen immer größere Datenmengen analysiert, gespeichert und übertragen werden. Um Engpässe oder gar Staus auf den Daten Highways zu vermeiden, wird es zunehmend wichtiger, den Datentransfer über das Netz - insbesondere von Bildern - möglichst schnell und kostengünstig durchzuführen. Software-Hersteller und Online-Anbieter versuchen folgerichtig, effiziente, der Anwendung angepaßte, Kompressionstechniken bereitzustellen, die die Information möglichst dichtgepackt übertragen. Im Wettstreit zwischenden verschiedenen Kompressionsverfahren gewinnen Wavelet-Algorithmen immer mehr an Bedeutung

    Fen and bog plant communities in the Aran valley, in the central Pyrenees

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    La Vall d’Aran està situada al vessant nord dels Pirineus, on el clima de tipus medioeuropeu i de muntanya amb una marcada influència atlàntica propicia una gran diversitat de molleres. En aquest treball presentem els resultats de l’estudi fitosociològic d’aquestes molleres, especialment d’aquelles que formen part de sistemes complexos (que n’inclouen d’ombrògenes, topògenes, solígenes i limnògenes). Hem seguit la metodologia de Braun-Blanquet per a l’aixecament dels inventaris i hem mesurat també alguns factors ambientals (pH i conductivitat de l’aigua lliure del sòl, profunditat de l’aigua freàtica i gruix de la capa de torba) a part de les variables topogràfiques bàsiques. Presentem 144 inventaris de 22 associacions (una d’elles diversificada en 4 subassociacions), 2 de les quals són noves descripcions, i 8 es documenten per primer cop dels Pirineus. La majoria d’associacions corresponen a la classe Scheuchzerio-Caricetea fuscae (molleres i torberes minerogèniques) i força menys es refereixen a torberes ombrogèniques de la classe Oxycocco-Sphagnetea o a la vegetació lacustre associada de les aliances Magnocaricion, Phragmition i Scorpidio-Utricularion minoris. Valorem la diversitat de torberes en forma de bony de la classe Oxycocco-Sphagnetea i la presència de molleres tremoloses del Caricion lasiocarpae, que constitueixen l’única representació dels Scheuchzerietalia a Catalunya. Reinterpretem les formacions dominades per Scirpus cespitosus, i proposem el nom Vaccinio microphylli-Sphagnetum capillifolii per al que fins ara s’ha anomenat Calluno-Sphagnetum subnitentis Casanovas 1992 (nom. inval.) Com a conclusió general, destaquem la singularitat de la Vall d’Aran per la diversitat i excepcionalitat de les comunitats de molleres que s’hi donen. A més, aquestes formen sistemes molt particulars pel que fa a la hidrologia i al mosaic de comunitats que acullen; en són exemples destacats els de bassa Nera, Planhòla d’Aiguamòg i pla de Tor.Given the topographic situation of the Aran valley, on the north side of the Pyrenees, the climate regimes (from medio-European to high mountain types) have a strong Atlantic influence. This, and the complex relief and bedrock assemblage of the area, enable the formation of great diversity of fens and bogs, covering from mediumsized to small areas. Here we present a phytosociological study of these vegetation units, and especially of those found in the complex systems, where ombrogenous, topogenous, soligenous and limnogenous mires may occur. We obtained field relevés according to the Braun-Blanquet approach, and recorded various associated environmental parameters (pH and conductivity of the soil water, depth of the phreatic water table, peat thickness), as well as topographic descriptors. By means of 144 relevés we discuss 22 associations (one of these split in 4 subassociations), from which 2 are new descriptions and 8 are firstly documented from the Pyrenees. Most of the associations treated are included in the vegetation class Scheuchzerio-Caricetea fuscae (fens), whereas few are referred to the Oxycocco-Sphagnetea ombrogenic bogs or to the neighbouring lacustrine alliances Magnocaricion, Phragmition and Scorpidio-Utricularion minoris. We discuss the diversity of the Oxycocco-Sphagnetea bog hummocks, and the occurrence of the Caricion lasiocarpae floating carpets, which are the sole Scheuchzerietalia representation in Catalonia. Other novelties are the reinterpretation of the Scirpus cespitosus communities, and the new name Vaccinio microphylli-Sphagnetum capillifolii, which properly refers to the Calluno- Sphagnetum subnitentis Casanovas 1992 (nom. inval.). As a general conclusion, we point out the singularity of the Aran valley, referred to the diversity and particularity of the fen and bog communities found. Moreover, these communities are combined into particular systems according to hydrologic aspects, which are especially diverse and outstanding at Bassa Nera, Planhòla d’Aiguamòg and Plan de Tor

    Discrete model for laser driven etching and microstructuring of metallic surfaces

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    We present a unidimensional discrete solid-on-solid model evolving in time using a kinetic Monte Carlo method to simulate micro-structuring of kerfs on metallic surfaces by means of laser-induced jet-chemical etching. The precise control of the passivation layer achieved by this technique is responsible for the high resolution of the structures. However, within a certain range of experimental parameters, the microstructuring of kerfs on stainless steel surfaces with a solution of H3PO4\mathrm{H}_3\mathrm{PO}_4 shows periodic ripples, which are considered to originate from an intrinsic dynamics. The model mimics a few of the various physical and chemical processes involved and within certain parameter ranges reproduces some morphological aspects of the structures, in particular ripple regimes. We analyze the range of values of laser beam power for the appearance of ripples in both experimental and simulated kerfs. The discrete model is an extension of one that has been used previously in the context of ion sputtering and is related to a noisy version of the Kuramoto-Sivashinsky equation used extensively in the field of pattern formation.Comment: Revised version. Etching probability distribution and new simulations adde
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