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Showing papers by "Free University of Berlin published in 2014"


Book ChapterDOI
01 Jan 2014
TL;DR: In this paper, Dzherbashian [Dzh60] defined a function with positive α 1 > 0, α 2 > 0 and real α 1, β 2, β 3, β 4, β 5, β 6, β 7, β 8, β 9, β 10, β 11, β 12, β 13, β 14, β 15, β 16, β 17, β 18, β 20, β 21, β 22, β 24
Abstract: Consider the function defined for \(\alpha _{1},\ \alpha _{2} \in \mathbb{R}\) (α 1 2 +α 2 2 ≠ 0) and \(\beta _{1},\beta _{2} \in \mathbb{C}\) by the series $$\displaystyle{ E_{\alpha _{1},\beta _{1};\alpha _{2},\beta _{2}}(z) \equiv \sum _{k=0}^{\infty } \frac{z^{k}} {\varGamma (\alpha _{1}k +\beta _{1})\varGamma (\alpha _{2}k +\beta _{2})}\ \ (z \in \mathbb{C}). }$$ (6.1.1) Such a function with positive α 1 > 0, α 2 > 0 and real \(\beta _{1},\beta _{2} \in \mathbb{R}\) was introduced by Dzherbashian [Dzh60].

919 citations


Journal ArticleDOI
TL;DR: New space-based observations of chlorophyll fluorescence enable an accurate, global, and time-resolved measurement of crop photosynthesis, which is not possible from any other remote vegetation measurement, and indicates that SIF data can help improve global models for more accurate projections of agricultural productivity and climate impact on crop yields.
Abstract: Photosynthesis is the process by which plants harvest sunlight to produce sugars from carbon dioxide and water. It is the primary source of energy for all life on Earth; hence it is important to understand how this process responds to climate change and human impact. However, model-based estimates of gross primary production (GPP, output from photosynthesis) are highly uncertain, in particular over heavily managed agricultural areas. Recent advances in spectroscopy enable the space-based monitoring of sun-induced chlorophyll fluorescence (SIF) from terrestrial plants. Here we demonstrate that spaceborne SIF retrievals provide a direct measure of the GPP of cropland and grassland ecosystems. Such a strong link with crop photosynthesis is not evident for traditional remotely sensed vegetation indices, nor for more complex carbon cycle models. We use SIF observations to provide a global perspective on agricultural productivity. Our SIF-based crop GPP estimates are 50–75% higher than results from state-of-the-art carbon cycle models over, for example, the US Corn Belt and the Indo-Gangetic Plain, implying that current models severely underestimate the role of management. Our results indicate that SIF data can help us improve our global models for more accurate projections of agricultural productivity and climate impact on crop yields. Extension of our approach to other ecosystems, along with increased observational capabilities for SIF in the near future, holds the prospect of reducing uncertainties in the modeling of the current and future carbon cycle.

782 citations


Journal ArticleDOI
TL;DR: Functional neuroimaging studies on music and emotion show that music can modulate activity in brain structures that are known to be crucially involved in emotion, such as the amygdala, nucleus accumbens, hypothalamus, hippocampus, insula, cingulate cortex and orbitofrontal cortex.
Abstract: Music is a universal feature of human societies, partly owing to its power to evoke strong emotions and influence moods. During the past decade, the investigation of the neural correlates of music-evoked emotions has been invaluable for the understanding of human emotion. Functional neuroimaging studies on music and emotion show that music can modulate activity in brain structures that are known to be crucially involved in emotion, such as the amygdala, nucleus accumbens, hypothalamus, hippocampus, insula, cingulate cortex and orbitofrontal cortex. The potential of music to modulate activity in these structures has important implications for the use of music in the treatment of psychiatric and neurological disorders.

752 citations


Journal ArticleDOI
TL;DR: This work used path analysis to determine whether compound indices detected more relationships between diversities of different organisms and traits than more basic indices, and demonstrated that while common diversity indices may appear interchangeable in simple analyses, when considering complex interactions, the choice of index can profoundly alter the interpretation of results.
Abstract: Biodiversity, a multidimensional property of natural systems, is difficult to quantify partly because of the multitude of indices proposed for this purpose. Indices aim to describe general properties of communities that allow us to compare different regions, taxa, and trophic levels. Therefore, they are of fundamental importance for environmental monitoring and conservation, although there is no consensus about which indices are more appropriate and informative. We tested several common diversity indices in a range of simple to complex statistical analyses in order to determine whether some were better suited for certain analyses than others. We used data collected around the focal plant Plantago lanceolata on 60 temperate grassland plots embedded in an agricultural landscape to explore relationships between the common diversity indices of species richness (S), Shannon's diversity (H'), Simpson's diversity (D-1), Simpson's dominance (D-2), Simpson's evenness (E), and Berger-Parker dominance (BP). We calculated each of these indices for herbaceous plants, arbuscular mycorrhizal fungi, aboveground arthropods, belowground insect larvae, and P.lanceolata molecular and chemical diversity. Including these trait-based measures of diversity allowed us to test whether or not they behaved similarly to the better studied species diversity. We used path analysis to determine whether compound indices detected more relationships between diversities of different organisms and traits than more basic indices. In the path models, more paths were significant when using H', even though all models except that with E were equally reliable. This demonstrates that while common diversity indices may appear interchangeable in simple analyses, when considering complex interactions, the choice of index can profoundly alter the interpretation of results. Data mining in order to identify the index producing the most significant results should be avoided, but simultaneously considering analyses using multiple indices can provide greater insight into the interactions in a system.

712 citations


Journal ArticleDOI
TL;DR: Recent progress in Markov state models, which reproduce the long-time statistical conformational dynamics of biomolecules using data from molecular dynamics simulations, is reviewed, considering theoretical and methodological advances, new software tools, and recent applications of these approaches in several domains of biochemistry and biophysics.

651 citations


Journal ArticleDOI
TL;DR: Current analytical methods to test mechanistic hypotheses and theories of protein-surface interactions will be discussed and special focus will be given to state-of-the-art bioinert and biospecific coatings and their applications in biomedicine.
Abstract: Protein adsorption is considered to be the most important factor of the interaction between polymeric biomaterials and body fluids or tissues. Water-mediated hydrophobic and hydration forces as well as electrostatic interactions are believed to be the major factors of protein adsorption. A systematic analysis of various monolayer systems has resulted in general guidelines, the so-called "Whitesides rules". These concepts have been successfully applied for designing various protein-resistant surfaces and are being studied to expand the understanding of protein-material interactions beyond existing limitations. Theories on the mechanisms of protein adsorption are constantly being improved due to the fast-developing analytical technologies. This Review is aimed at improving these empirical guidelines with regard to present theoretical and analytical advances. Current analytical methods to test mechanistic hypotheses and theories of protein-surface interactions will be discussed. Special focus will be given to state-of-the-art bioinert and biospecific coatings and their applications in biomedicine.

587 citations


Journal ArticleDOI
TL;DR: Resilience management goes beyond risk management to address the complexities of large integrated systems and the uncertainty of future threats, especially those associated with climate change as mentioned in this paper, which is a common theme in our work.
Abstract: Resilience management goes beyond risk management to address the complexities of large integrated systems and the uncertainty of future threats, especially those associated with climate change.

508 citations


Journal ArticleDOI
09 May 2014-Science
TL;DR: This work shows thatVRAC defines a class of anion channels, suggests that VRAC is identical to the volume-sensitive organic osmolyte/anion channel VSOAC, and explains the heterogeneity of native VRAC currents.
Abstract: Regulation of cell volume is critical for many cellular and organismal functions, yet the molecular identity of a key player, the volume-regulated anion channel VRAC, has remained unknown. A genome-wide small interfering RNA screen in mammalian cells identified LRRC8A as a VRAC component. LRRC8A formed heteromers with other LRRC8 multispan membrane proteins. Genomic disruption of LRRC8A ablated VRAC currents. Cells with disruption of all five LRRC8 genes required LRRC8A cotransfection with other LRRC8 isoforms to reconstitute VRAC currents. The isoform combination determined VRAC inactivation kinetics. Taurine flux and regulatory volume decrease also depended on LRRC8 proteins. Our work shows that VRAC defines a class of anion channels, suggests that VRAC is identical to the volume-sensitive organic osmolyte/anion channel VSOAC, and explains the heterogeneity of native VRAC currents.

493 citations


Journal ArticleDOI
TL;DR: A bottom-up solution synthesis of long (>200 nm) liquid-phase-processable GNRs with a well-defined structure and a large optical bandgap is reported, which may prove useful for fundamental studies of graphene nanostructures, as well as the development of GNR-based nanoelectronics.
Abstract: Liquid-phase-processable graphene nanoribbons (GNRs) over 200 nm long and with well-defined structures have now been synthesized by a bottom-up method, and are found to have a large optical bandgap of 1.88 eV. Scanning probe microscopy revealed highly ordered self-assembled monolayers of the GNRs, and the high intrinsic charge-carrier mobility of individual ribbons was characterized by terahertz spectroscopy.

434 citations


Journal ArticleDOI
TL;DR: In this paper, the authors used spin-resolved photoemission spectroscopy with p-polarized light in topological insulator Bi2Se3 thin films.
Abstract: Understanding the spin-texture behaviour of boundary modes in ultrathin topological insulator films is critically essential for the design and fabrication of functional nanodevices. Here, by using spin-resolved photoemission spectroscopy with p-polarized light in topological insulator Bi2Se3 thin films, we report tunnelling-dependent evolution of spin configuration in topological insulator thin films across the metal-to-insulator transition. We report a systematic binding energy- and wavevector-dependent spin polarization for the topological surface electrons in the ultrathin gapped-Dirac-cone limit. The polarization decreases significantly with enhanced tunnelling realized systematically in thin insulating films, whereas magnitude of the polarization saturates to the bulk limit faster at larger wavevectors in thicker metallic films. We present a theoretical model that captures this delicate relationship between quantum tunnelling and Fermi surface spin polarization. Our high-resolution spin-based spectroscopic results suggest that the polarization current can be tuned to zero in thin insulating films forming the basis for a future spin-switch nanodevice.

405 citations


Journal ArticleDOI
TL;DR: In this paper, the authors evaluate the potential of the OCO-2 for retrievals of chlorophyll fluorescence and also its dependence on clouds and aerosols, and find that the single-measurement precision is 0.3-0.5 Wm(exp -2)sr(exp-1) nm(exp −1) (15-25% of typical peak values), better than current measurements from space but still difficult to interpret on a single sounding basis.

Journal ArticleDOI
TL;DR: In this paper, the authors investigate to what extent the personality of individuals influences the entry decision into and the exit decision from self-employment, based on a large, representative German household panel.
Abstract: Based on a large, representative German household panel, we investigate to what extent the personality of individuals influences the entry decision into and the exit decision from self-employment. We reveal that some traits, such as openness to experience, extraversion, and risk tolerance affect entry, but different ones, such as agreeableness or different parameter values of risk tolerance, affect exit from self-employment. Only locus of control has a similar influence on the entry and exit decisions. The explanatory power of all observed traits among all observable variables amounts to 30 %, with risk tolerance, locus of control, and openness having the highest explanatory power.

Journal ArticleDOI
TL;DR: The method proposed here is to first define a basis set able to capture the relevant conformational transitions, then compute the respective correlation matrices, and then to compute their dominant eigenvalues and eigenvectors, thus obtaining the key ingredients of the slow kinetics.
Abstract: The eigenvalues and eigenvectors of the molecular dynamics propagator (or transfer operator) contain the essential information about the molecular thermodynamics and kinetics. This includes the stationary distribution, the metastable states, and state-to-state transition rates. Here, we present a variational approach for computing these dominant eigenvalues and eigenvectors. This approach is analogous to the variational approach used for computing stationary states in quantum mechanics. A corresponding method of linear variation is formulated. It is shown that the matrices needed for the linear variation method are correlation matrices that can be estimated from simple MD simulations for a given basis set. The method proposed here is thus to first define a basis set able to capture the relevant conformational transitions, then compute the respective correlation matrices, and then to compute their dominant eigenvalues and eigenvectors, thus obtaining the key ingredients of the slow kinetics.

Journal ArticleDOI
TL;DR: In this paper, the seasonal cycle of photosynthesis as estimated from satellite fluorescence retrievals at wavelengths surrounding the 740nm emission feature was examined, and the seasonality of absorbed photosynthetically-active radiation (APAR) derived with reflectances from the MODerate-resolution Imaging Spectroradiometer (MODIS).

Journal ArticleDOI
TL;DR: In this article, a review of nanostructured CuxO focusing on their material properties, methods of synthesis and an overview of various applications that have been associated with the nanostructure of the oxides of copper is presented.
Abstract: The oxides of copper (CuxO) are fascinating materials due to their remarkable optical, electrical, thermal and magnetic properties. Nanostructuring of CuxO can further enhance the performance of this important functional material and provide it with unique properties that do not exist in its bulk form. Three distinctly different phases of CuxO, mainly CuO, Cu2O and Cu4O3, can be prepared by numerous synthesis techniques including, vapour deposition and liquid phase chemical methods. In this article, we present a review of nanostructured CuxO focusing on their material properties, methods of synthesis and an overview of various applications that have been associated with nanostructured CuxO.

Journal ArticleDOI
06 Nov 2014-Nature
TL;DR: This study finds character displacement between species and increased biodiversity effects when plants had been selected over 8 years in species mixtures rather than in monocultures, and demonstrates a novel mechanism for the increase in biodiversity effects.
Abstract: In experimental plant communities, relationships between biodiversity and ecosystem functioning have been found to strengthen over time, a fact often attributed to increased resource complementarity between species in mixtures and negative plant–soil feedbacks in monocultures. Here we show that selection for niche differentiation between species can drive this increasing biodiversity effect. Growing 12 grassland species in test monocultures and mixtures, we found character displacement between species and increased biodiversity effects when plants had been selected over 8 years in species mixtures rather than in monocultures. When grown in mixtures, relative differences in height and specific leaf area between plant species selected in mixtures (mixture types) were greater than between species selected in monocultures (monoculture types). Furthermore, net biodiversity and complementarity effects were greater in mixtures of mixture types than in mixtures of monoculture types. Our study demonstrates a novel mechanism for the increase in biodiversity effects: selection for increased niche differentiation through character displacement. Selection in diverse mixtures may therefore increase species coexistence and ecosystem functioning in natural communities and may also allow increased mixture yields in agriculture or forestry. However, loss of biodiversity and prolonged selection of crops in monoculture may compromise this potential for selection in the longer term.

Journal ArticleDOI
TL;DR: A transparent, conductive, and flexible electrode is demonstrated, based on an inexpensive and easily manufacturable metallic network formed by depositing metals onto a template film.
Abstract: A transparent, conductive, and flexible electrode is demonstrated. It is based on an inexpensive and easily manufacturable metallic network formed by depositing metals onto a template film. This electrode shows excellent electro-optical properties, with the figure of merit ranging from 300 to 700, and transmittance from 82% (~4.3 Ω sq(-1) ) to 45% (~0.5 Ω sq(-1) ).

Journal ArticleDOI
28 Feb 2014-PLOS ONE
TL;DR: Overall, sad mood and concentration problems had the highest unique associations with impairment and were among the most debilitating symptoms in all five domains.
Abstract: Previous studies have established that scores on Major Depressive Disorder scales are correlated with measures of impairment of psychosocial functioning. It remains unclear, however, whether individual depressive symptoms vary in their effect on impairment, and if so, what the magnitude of these differences might be. We analyzed data from 3,703 depressed outpatients in the first treatment stage of the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study. Participants reported on the severity of 14 depressive symptoms, and stated to what degree their depression impaired psychosocial functioning (in general, and in the five domains work, home management, social activities, private activities, and close relationships). We tested whether symptoms differed in their associations with impairment, estimated unique shared variances of each symptom with impairment to assess the degree of difference, and examined whether symptoms had variable impacts across impairment domains. Our results show that symptoms varied substantially in their associations with impairment, and contributed to the total explained variance in a range from 0.7% (hypersomnia) to 20.9% (sad mood). Furthermore, symptoms had significantly different impacts on the five impairment domains. Overall, sad mood and concentration problems had the highest unique associations with impairment and were among the most debilitating symptoms in all five domains. Our findings are in line with a growing chorus of voices suggesting that symptom sum-scores obfuscate relevant differences between depressed patients and that substantial rewards will come from close attention to individual depression symptoms.

Journal ArticleDOI
07 Mar 2014-Science
TL;DR: A proposed ruling by the U.S. Environmental Protection Agency (EPA) aimed at clarifying which bodies of water that flow intermittently are protected under law has provoked conflict between developers and environmental advocates as mentioned in this paper.
Abstract: A proposed ruling by the U.S. Environmental Protection Agency (EPA), aimed at clarifying which bodies of water that flow intermittently are protected under law ( 1 ), has provoked conflict between developers and environmental advocates. Some argue that temporary streams and rivers, defined as waterways that cease to flow at some points in space and time along their course (see the figure, left) ( Fig. 1) ( 2 ), are essential to the integrity of entire river networks. Others argue that full protection will be too costly. Similar concerns extend far beyond the United States. Debate over how to treat temporary waterways in water-policy frameworks is ongoing ( 3 ), particularly because some large permanent rivers are shifting to temporary because of climate change and extraction of water ( 4 ). Even without human-induced changes, flow intermittency is part of the natural hydrology for streams and rivers globally.

Journal ArticleDOI
01 Mar 2014
TL;DR: Recommendations are provided that could promote the study of negative effects in Internet interventions with the aim of increasing the knowledge of its occurrence and characteristics, and advising researchers to systematically probe for negative effects whenever conducting clinical trials involving Internet interventions.
Abstract: Internet interventions have great potential for alleviating emotional distress, promoting mental health, and enhancing well-being. Numerous clinical trials have demonstrated their efficacy for a number of psychiatric conditions, and interventions delivered via the Internet will likely become a common alternative to face-to-face treatment. Meanwhile, research has paid little attention to the negative effects associated with treatment, warranting further investigation of the possibility that some patients might deteriorate or encounter adverse events despite receiving best available care. Evidence from research of face-to-face treatment suggests that negative effects afflict 5–10% of all patients undergoing treatment in terms of deterioration. However, there is currently a lack of consensus on how to define and measure negative effects in psychotherapy research in general, leaving researchers without practical guidelines for monitoring and reporting negative effects in clinical trials. The current paper therefore seeks to provide recommendations that could promote the study of negative effects in Internet interventions with the aim of increasing the knowledge of its occurrence and characteristics. Ten leading experts in the field of Internet interventions were invited to participate and share their perspective on how to explore negative effects, using the Delphi technique to facilitate a dialog and reach an agreement. The authors discuss the importance of conducting research on negative effects in order to further the understanding of its incidence and different features. Suggestions on how to classify and measure negative effects in Internet interventions are proposed, involving methods from both quantitative and qualitative research. Potential mechanisms underlying negative effects are also discussed, differentiating common factors shared with face-to-face treatments from those unique to treatments delivered via the Internet. The authors conclude that negative effects are to be expected and need to be acknowledged to a greater extent, advising researchers to systematically probe for negative effects whenever conducting clinical trials involving Internet interventions, as well as to share their findings in scientific journals.

Journal ArticleDOI
TL;DR: In this article, the authors examined the psychometric properties of short scales (with three items) and single-item measures for two core motivational-affective constructs (i.e., academic anxiety and academic self-concept) by conducting systematic comparisons with corresponding long scales across school subjects and within different subject domains.

Journal ArticleDOI
TL;DR: In this paper, the authors contrast traditional views with broader perspectives that are emerging from an improved understanding of the climatic context of floods, and they come to the following conclusions: (1) extending the traditional system boundaries (local catchment, recent decades, hydrological/hydraulic processes) opens up exciting possibilities for better understanding and improved tools for flood risk assessment and management.
Abstract: Flood estimation and flood management have traditionally been the domain of hydrologists, water resources engineers and statisticians, and disciplinary approaches abound. Dominant views have been shaped; one example is the catchment perspective: floods are formed and influenced by the interaction of local, catchment-specific characteristics, such as meteorology, topography and geology. These traditional views have been beneficial, but they have a narrow framing. In this paper we contrast traditional views with broader perspectives that are emerging from an improved understanding of the climatic context of floods. We come to the following conclusions: (1) extending the traditional system boundaries (local catchment, recent decades, hydrological/hydraulic processes) opens up exciting possibilities for better understanding and improved tools for flood risk assessment and management. (2) Statistical approaches in flood estimation need to be complemented by the search for the causal mechanisms and dominant processes in the atmosphere, catchment and river system that leave their fingerprints on flood characteristics. (3) Natural climate variability leads to time-varying flood characteristics, and this variation may be partially quantifiable and predictable, with the perspective of dynamic, climate-informed flood risk management. (4) Efforts are needed to fully account for factors that contribute to changes in all three risk components (hazard, exposure, vulnerability) and to better understand the interactions between society and floods. (5) Given the global scale and societal importance, we call for the organization of an international multidisciplinary collaboration and data-sharing initiative to further understand the links between climate and flooding and to advance flood research.

Proceedings ArticleDOI
24 Sep 2014
TL;DR: In this paper, the feasibility, advantages, and challenges of an ICN-based approach in the Internet of Things are explored, and several interoperable CCN enhancements are then proposed and evaluated.
Abstract: This paper explores the feasibility, advantages, and challenges of an ICN-based approach in the Internet of Things. We report on the first NDN experiments in a life-size IoT deployment, spread over tens of rooms on several floors of a building. Based on the insights gained with these experiments, the paper analyses the shortcomings of CCN applied to IoT. Several interoperable CCN enhancements are then proposed and evaluated. We significantly decreased control traffic (i.e., interest messages) and leverage data path and caching to match IoT requirements in terms of energy and bandwidth constraints. Our optimizations increase content availability in case of IoT nodes with intermittent activity. This paper also provides the first experimental comparison of CCN with the common IoT standards 6LoWPAN/RPL/UDP.

Journal ArticleDOI
TL;DR: Fauna Europaea is Europe's main zoological taxonomic index, making the scientific names and distributions of all living, currently known, multicellular, European land and freshwater animals species integrally available in one authoritative database.
Abstract: Fauna Europaea is Europe's main zoological taxonomic index, making the scientific names and distributions of all living, currently known, multicellular, European land and freshwater animals species integrally available in one authoritative database. Fauna Europaea covers about 260,000 taxon names, including 145,000 accepted (sub)species, assembled by a

Journal Article
TL;DR: In this paper, a review of nanostructured CuxO focusing on their material properties, methods of synthesis and an overview of various applications that have been associated with the nanostructure of the oxides of copper is presented.
Abstract: The oxides of copper (CuxO) are fascinating materials due to their remarkable optical, electrical, thermal and magnetic properties. Nanostructuring of CuxO can further enhance the performance of this important functional material and provide it with unique properties that do not exist in its bulk form. Three distinctly different phases of CuxO, mainly CuO, Cu2O and Cu4O3, can be prepared by numerous synthesis techniques including, vapour deposition and liquid phase chemical methods. In this article, we present a review of nanostructured CuxO focusing on their material properties, methods of synthesis and an overview of various applications that have been associated with nanostructured CuxO.

Journal ArticleDOI
19 Mar 2014-PLOS ONE
TL;DR: It is concluded that non-lethal doses of the three neonicotinoids tested either block the retrieval of exploratory navigation memory or alter this form of navigation memory in honeybee navigation.
Abstract: Three neonicotinoids, imidacloprid, clothianidin and thiacloprid, agonists of the nicotinic acetylcholine receptor in the central brain of insects, were applied at non-lethal doses in order to test their effects on honeybee navigation. A catch-and-release experimental design was applied in which feeder trained bees were caught when arriving at the feeder, treated with one of the neonicotinoids, and released 1.5 hours later at a remote site. The flight paths of individual bees were tracked with harmonic radar. The initial flight phase controlled by the recently acquired navigation memory (vector memory) was less compromised than the second phase that leads the animal back to the hive (homing flight). The rate of successful return was significantly lower in treated bees, the probability of a correct turn at a salient landscape structure was reduced, and less directed flights during homing flights were performed. Since the homing phase in catch-and-release experiments documents the ability of a foraging honeybee to activate a remote memory acquired during its exploratory orientation flights, we conclude that non-lethal doses of the three neonicotinoids tested either block the retrieval of exploratory navigation memory or alter this form of navigation memory. These findings are discussed in the context of the application of neonicotinoids in plant protection.

Journal ArticleDOI
TL;DR: It is shown that top-of-canopy SIF measurements from space are sensitive to Vcmax at the ecosystem level, and an approach to invert Vc Max from SIF data is presented, suggesting the potential for global, time-resolved estimates of Vc max.
Abstract: Photosynthesis simulations by terrestrial biosphere models are usually based on the Farquhar’s model, in which the maximum rate of carboxylation (Vcmax) is a key control parameter of photosynthetic capacity. Even though Vcmax is known to vary substantially in space and time in response to environmental controls, it is typically parameterized in models with tabulated values associated to plant functional types. Remote sensing can be used to produce a spatially continuous and temporally resolved view on photosynthetic efficiency, but traditional vegetation observations based on spectral reflectance lack a direct link to plant photochemical processes. Alternatively, recent space-borne measurements of sun-induced chlorophyll fluorescence (SIF) can offer an observational constraint on photosynthesis simulations. Here, we show that top-of-canopy SIF measurements from space are sensitive to Vcmax at the ecosystem level, and present an approach to invert Vcmax from SIF data. We use the Soil-Canopy Observation of Photosynthesis and Energy (SCOPE) balance model to derive empirical relationships between seasonal Vcmax and SIF which are used to solve the inverse problem. We evaluate our Vcmax estimation method at six agricultural flux tower sites in the midwestern US using spaced-based SIF retrievals. Our Vcmax estimates agree well with literature values for corn and soybean plants (average values of 37 and 101 lmol m � 2 s � 1 , respectively) and show plausible seasonal patterns. The effect of the updated seasonally varying Vcmax parameterization on simulated gross primary productivity (GPP) is tested by comparing to simulations with fixed Vcmax values. Validation against flux tower observations demonstrate that simulations of GPP and light use efficiency improve significantly when our time-resolved Vcmax estimates from SIF are used, with R 2 for GPP comparisons increasing from 0.85 to 0.93, and for light use efficiency from 0.44 to 0.83. Our results support the use of space-based SIF data as a proxy for photosynthetic capacity and suggest the potential for global, time-resolved estimates of Vcmax.

Proceedings ArticleDOI
TL;DR: The first NDN experiments in a life-size IoT deployment, spread over tens of rooms on several floors of a building, are reported on, and the shortcomings of CCN applied to IoT are analyzed.
Abstract: This paper explores the feasibility, advantages, and challenges of an ICN-based approach in the Internet of Things. We report on the first NDN experiments in a life-size IoT deployment, spread over tens of rooms on several floors of a building. Based on the insights gained with these experiments, the paper analyses the shortcomings of CCN applied to IoT. Several interoperable CCN enhancements are then proposed and evaluated. We significantly decreased control traffic (i.e., interest messages) and leverage data path and caching to match IoT requirements in terms of energy and bandwidth constraints. Our optimizations increase content availability in case of IoT nodes with intermittent activity. This paper also provides the first experimental comparison of CCN with the common IoT standards 6LoWPAN/RPL/UDP.

Journal ArticleDOI
TL;DR: In this article, an aggregated model of renewable wind and solar power generation forecast is proposed to support the quantification of the operational reserve for day-ahead and real-time scheduling.
Abstract: Operational controls are designed to support the integration of wind and solar power within microgrids. An aggregated model of renewable wind and solar power generation forecast is proposed to support the quantification of the operational reserve for day-ahead and real-time scheduling. Then, a droop control for power electronic converters connected to battery storage is developed and tested. Compared with the existing droop controls, it is distinguished in that the droop curves are set as a function of the storage state-of-charge (SOC) and can become asymmetric. The adaptation of the slopes ensures that the power output supports the terminal voltage while at the same keeping the SOC within a target range of desired operational reserve. This is shown to maintain the equilibrium of the microgrid's real-time supply and demand. The controls are implemented for the special case of a dc microgrid that is vertically integrated within a high-rise host building of an urban area. Previously untapped wind and solar power are harvested on the roof and sides of a tower, thereby supporting delivery to electric vehicles on the ground. The microgrid vertically integrates with the host building without creating a large footprint.

Journal ArticleDOI
17 Apr 2014-Immunity
TL;DR: The findings show that eosinophils are important players for immune homeostasis in gut-associated tissues and add to data suggesting that eOSinophil-specific depletion model can promote tissue integrity.