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Showing papers by "Free University of Berlin published in 2011"


Journal ArticleDOI
TL;DR: A review of the literature reveals a significant number of early studies on biochar-type materials as soil amendments either for managing pathogens, as inoculant carriers or for manipulative experiments to sorb signaling compounds or toxins as mentioned in this paper.
Abstract: Soil amendment with biochar is evaluated globally as a means to improve soil fertility and to mitigate climate change. However, the effects of biochar on soil biota have received much less attention than its effects on soil chemical properties. A review of the literature reveals a significant number of early studies on biochar-type materials as soil amendments either for managing pathogens, as inoculant carriers or for manipulative experiments to sorb signaling compounds or toxins. However, no studies exist in the soil biologyliterature that recognize the observed largevariations ofbiochar physico-chemical properties. This shortcoming has hampered insight into mechanisms by which biochar influences soil microorganisms, fauna and plant roots. Additional factors limiting meaningful interpretation of many datasets are the clearly demonstrated sorption properties that interfere with standard extraction procedures for soil microbial biomass or enzyme assays, and the confounding effects of varying amounts of minerals. In most studies, microbial biomass has been found to increase as a result of biochar additions, with significant changes in microbial community composition and enzyme activities that may explain biogeochemical effects of biochar on element cycles, plant pathogens, and crop growth. Yet, very little is known about the mechanisms through which biochar affects microbial abundance and community composition. The effects of biochar on soil fauna are even less understood than its effects on microorganisms, apart from several notable studies on earthworms. It is clear, however, that sorption phenomena, pH and physical properties of biochars such as pore structure, surface area and mineral matter play important roles in determining how different biochars affect soil biota. Observations on microbial dynamics lead to the conclusion of a possible improved resource use due to co-location of various resources in and around biochars. Sorption and therebyinactivation of growth-inhibiting substances likelyplaysa rolefor increased abundance of soil biota. No evidence exists so far for direct negative effects of biochars on plant roots. Occasionally observed decreases in abundance of mycorrhizal fungi are likely caused by concomitant increases in nutrient availability,reducing theneedfor symbionts.Inthe shortterm,therelease ofavarietyoforganic molecules from fresh biochar may in some cases be responsible for increases or decreases in abundance and activity of soil biota. A road map for future biochar research must include a systematic appreciation of different biochar-types and basic manipulative experiments that unambiguously identify the interactions between biochar and soil biota.

3,612 citations


Journal ArticleDOI
TL;DR: In this article, it was shown that a key operation, the braiding of non-Abelian anyons, can be implemented using one-dimensional semiconducting wires, such wires can be driven into a topological phase supporting long-sought particles known as Majorana fermions that can encode topological qubits.
Abstract: The synthesis of a quantum computer remains an ongoing challenge in modern physics. Whereas decoherence stymies most approaches, topological quantum computation schemes evade decoherence at the hardware level by storing quantum information non-locally. Here we establish that a key operation—braiding of non-Abelian anyons—can be implemented using one-dimensional semiconducting wires. Such wires can be driven into a topological phase supporting long-sought particles known as Majorana fermions that can encode topological qubits. We show that in wire networks, Majorana fermions can be meaningfully braided by simply adjusting gate voltages, and that they exhibit non-Abelian statistics like vortices in a p+ip superconductor. We propose experimental set-ups that enable probing of the Majorana fusion rules and the efficient exchange of arbitrary numbers of Majorana fermions. This work should open a new direction in topological quantum computation that benefits from physical transparency and experimental feasibility.

1,376 citations


Proceedings ArticleDOI
07 Sep 2011
TL;DR: DBpedia Spotlight, a system for automatically annotating text documents with DBpedia URIs, is developed, and results are evaluated in light of three baselines and six publicly available annotation systems, demonstrating the competitiveness of the system.
Abstract: Interlinking text documents with Linked Open Data enables the Web of Data to be used as background knowledge within document-oriented applications such as search and faceted browsing. As a step towards interconnecting the Web of Documents with the Web of Data, we developed DBpedia Spotlight, a system for automatically annotating text documents with DBpedia URIs. DBpedia Spotlight allows users to configure the annotations to their specific needs through the DBpedia Ontology and quality measures such as prominence, topical pertinence, contextual ambiguity and disambiguation confidence. We compare our approach with the state of the art in disambiguation, and evaluate our results in light of three baselines and six publicly available annotation systems, demonstrating the competitiveness of our system. DBpedia Spotlight is shared as open source and deployed as a Web Service freely available for public use.

1,228 citations


Journal ArticleDOI
16 Sep 2011-Science
TL;DR: Anti-HIV broadly neutralizing antibodies with similar specificities and modes of binding were found in multiple HIV-infected individuals, and cloned 576 new HIV antibodies from four unrelated individuals to determine whether they are part of a larger group of related molecules.
Abstract: Passive transfer of broadly neutralizing HIV antibodies can prevent infection, which suggests that vaccines that elicit such antibodies would be protective. Thus far, however, few broadly neutralizing HIV antibodies that occur naturally have been characterized. To determine whether these antibodies are part of a larger group of related molecules, we cloned 576 new HIV antibodies from four unrelated individuals. All four individuals produced expanded clones of potent broadly neutralizing CD4-binding-site antibodies that mimic binding to CD4. Despite extensive hypermutation, the new antibodies shared a consensus sequence of 68 immunoglobulin H (IgH) chain amino acids and arise independently from two related IgH genes. Comparison of the crystal structure of one of the antibodies to the broadly neutralizing antibody VRC01 revealed conservation of the contacts to the HIV spike.

1,110 citations


Journal ArticleDOI
TL;DR: An upper bound for the approximation error made by modeling molecular dynamics with a Markov chain is described and it is shown that this error can be made arbitrarily small with surprisingly little effort.
Abstract: Markov state models of molecular kinetics (MSMs), in which the long-time statistical dynamics of a molecule is approximated by a Markov chain on a discrete partition of configuration space, have seen widespread use in recent years. This approach has many appealing characteristics compared to straightforward molecular dynamics simulation and analysis, including the potential to mitigate the sampling problem by extracting long-time kinetic information from short trajectories and the ability to straightforwardly calculate expectation values and statistical uncertainties of various stationary and dynamical molecular observables. In this paper, we summarize the current state of the art in generation and validation of MSMs and give some important new results. We describe an upper bound for the approximation error made by modeling molecular dynamics with a MSM and we show that this error can be made arbitrarily small with surprisingly little effort. In contrast to previous practice, it becomes clear that the best MSM is not obtained by the most metastable discretization, but the MSM can be much improved if non-metastable states are introduced near the transition states. Moreover, we show that it is not necessary to resolve all slow processes by the state space partitioning, but individual dynamical processes of interest can be resolved separately. We also present an efficient estimator for reversible transition matrices and a robust test to validate that a MSM reproduces the kinetics of the molecular dynamics data.

1,082 citations


Journal ArticleDOI
TL;DR: Recommendations were developed based on literature review using the GRADE system, discussion integrating the literature with the collective experience of the participants and critical review by an impartial jury and emphasis was placed on the principle that recommendations should be based not only on the quality of the data but also tradeoffs and translation into practice.
Abstract: Subarachnoid hemorrhage (SAH) is an acute cerebrovascular event which can have devastating effects on the central nervous system as well as a profound impact on several other organs SAH patients are routinely admitted to an intensive care unit and are cared for by a multidisciplinary team A lack of high quality data has led to numerous approaches to management and limited guidance on choosing among them Existing guidelines emphasize risk factors, prevention, natural history, and prevention of rebleeding, but provide limited discussion of the complex critical care issues involved in the care of SAH patients The Neurocritical Care Society organized an international, multidisciplinary consensus conference on the critical care management of SAH to address this need Experts from neurocritical care, neurosurgery, neurology, interventional neuroradiology, and neuroanesthesiology from Europe and North America were recruited based on their publications and expertise A jury of four experienced neurointensivists was selected for their experience in clinical investigations and development of practice guidelines Recommendations were developed based on literature review using the GRADE system, discussion integrating the literature with the collective experience of the participants and critical review by an impartial jury Recommendations were developed using the GRADE system Emphasis was placed on the principle that recommendations should be based not only on the quality of the data but also tradeoffs and translation into practice Strong consideration was given to providing guidance and recommendations for all issues faced in the daily management of SAH patients, even in the absence of high quality data

884 citations


Journal ArticleDOI
Jo Ann Banks1, Tomoaki Nishiyama2, Mitsuyasu Hasebe3, Mitsuyasu Hasebe4, John L. Bowman5, John L. Bowman6, Michael Gribskov1, Claude W. dePamphilis7, Victor A. Albert8, Naoki Aono3, Tsuyoshi Aoyama4, Tsuyoshi Aoyama3, Barbara A. Ambrose9, Neil W. Ashton10, Michael J. Axtell7, Elizabeth I. Barker10, Michael S. Barker11, Jeffrey L. Bennetzen12, Nicholas D. Bonawitz1, Clint Chapple1, Chaoyang Cheng, Luiz Gustavo Guedes Corrêa13, Michael Dacre14, Jeremy D. DeBarry12, Ingo Dreyer13, Marek Eliáš15, Eric M. Engstrom16, Mark Estelle17, Liang Feng12, Cédric Finet18, Sandra K. Floyd6, Wolf B. Frommer19, Tomomichi Fujita20, Lydia Gramzow21, Michael Gutensohn1, Michael Gutensohn22, Jesper Harholt23, Mitsuru Hattori24, Mitsuru Hattori25, Alexander Heyl26, Tadayoshi Hirai27, Yuji Hiwatashi3, Yuji Hiwatashi4, Masaki Ishikawa, Mineko Iwata, Kenneth G. Karol9, Barbara Koehler13, Uener Kolukisaoglu28, Uener Kolukisaoglu29, Minoru Kubo, Tetsuya Kurata30, Sylvie Lalonde19, Kejie Li1, Ying Li31, Ying Li1, Amy Litt9, Eric Lyons32, Gerard Manning14, Takeshi Maruyama20, Todd P. Michael33, Koji Mikami20, Saori Miyazaki34, Saori Miyazaki3, Shin-Ichi Morinaga3, Shin-Ichi Morinaga24, TakashiMurata3, TakashiMurata4, Bernd Mueller-Roeber35, David R. Nelson36, Mari Obara, Yasuko Oguri, Richard G. Olmstead37, Naoko T. Onodera38, Bent O. Petersen23, Birgit Pils39, Michael J. Prigge17, Stefan A. Rensing40, Diego Mauricio Riaño-Pachón41, Diego Mauricio Riaño-Pachón35, Alison W. Roberts42, Yoshikatsu Sato, Henrik Vibe Scheller32, Henrik Vibe Scheller43, Burkhard Schulz1, Christian Schulz44, Eugene V. Shakirov45, Nakako Shibagaki46, Naoki Shinohara20, Dorothy E. Shippen45, Iben Sørensen23, Iben Sørensen47, Ryo Sotooka20, Nagisa Sugimoto, Mamoru Sugita25, Naomi Sumikawa3, Milos Tanurdzic48, Günter Theißen21, Peter Ulvskov23, Sachiko Wakazuki, Jing-Ke Weng1, Jing-Ke Weng14, William G.T. Willats23, Daniel Wipf49, Paul G. Wolf50, Lixing Yang12, Andreas Zimmer40, Qihui Zhu12, Therese Mitros32, Uffe Hellsten51, Dominique Loqué43, Robert Otillar51, Asaf Salamov51, Jeremy Schmutz51, Harris Shapiro51, Erika Lindquist51, Susan Lucas51, Daniel S. Rokhsar51, Daniel S. Rokhsar32, Igor V. Grigoriev51 
20 May 2011-Science
TL;DR: The genome sequence of the lycophyte Selaginella moellendorffii (Selaginella), the first nonseed vascular plant genome reported, is reported, finding that the transition from a gametophytes- to a sporophyte-dominated life cycle required far fewer new genes than the Transition from a non Seed vascular to a flowering plant.
Abstract: Vascular plants appeared ~410 million years ago, then diverged into several lineages of which only two survive: the euphyllophytes (ferns and seed plants) and the lycophytes. We report here the genome sequence of the lycophyte Selaginella moellendorffii (Selaginella), the first nonseed vascular plant genome reported. By comparing gene content in evolutionarily diverse taxa, we found that the transition from a gametophyte- to a sporophyte-dominated life cycle required far fewer new genes than the transition from a nonseed vascular to a flowering plant, whereas secondary metabolic genes expanded extensively and in parallel in the lycophyte and angiosperm lineages. Selaginella differs in posttranscriptional gene regulation, including small RNA regulation of repetitive elements, an absence of the trans-acting small interfering RNA pathway, and extensive RNA editing of organellar genes.

750 citations


Journal ArticleDOI
TL;DR: In this paper, a review of hybrid renewable/alternative energy (RE/AE) power generation systems focusing on energy sustainability is presented, highlighting some important issues and challenges in the design and energy management of hybrid RE/AE systems.
Abstract: This paper, prepared by a special task force of the IEEE PES Renewable Technologies Subcommittee, is a review of hybrid renewable/alternative energy (RE/AE) power generation systems focusing on energy sustainability. It highlights some important issues and challenges in the design and energy management of hybrid RE/AE systems. System configurations, generation unit sizing, storage needs, and energy management and control are addressed. Statistics on the current status and future trend of renewable power generation, as well as some critical challenges facing the widespread deployment of RE/AE power generation technologies and vision for future research in this area are also presented. The comprehensive list of references given at the end of the paper should be helpful to researchers working in this area.

701 citations


Journal ArticleDOI
TL;DR: Under normal conditions, although CK deficiency increased the sensitivity of plants to exogenous ABA, it caused a downregulation of key ABA biosynthetic genes, leading to a significant reduction in endogenous ABA levels in CK-deficient plants relative to the wild type.
Abstract: Cytokinins (CKs) regulate plant growth and development via a complex network of CK signaling. Here, we perform functional analyses with CK-deficient plants to provide direct evidence that CKs negatively regulate salt and drought stress signaling. All CK-deficient plants with reduced levels of various CKs exhibited a strong stress-tolerant phenotype that was associated with increased cell membrane integrity and abscisic acid (ABA) hypersensitivity rather than stomatal density and ABA-mediated stomatal closure. Expression of the Arabidopsis thaliana ISOPENTENYL-TRANSFERASE genes involved in the biosynthesis of bioactive CKs and the majority of the Arabidopsis CYTOKININ OXIDASES/DEHYDROGENASES genes was repressed by stress and ABA treatments, leading to a decrease in biologically active CK contents. These results demonstrate a novel mechanism for survival under abiotic stress conditions via the homeostatic regulation of steady state CK levels. Additionally, under normal conditions, although CK deficiency increased the sensitivity of plants to exogenous ABA, it caused a downregulation of key ABA biosynthetic genes, leading to a significant reduction in endogenous ABA levels in CK-deficient plants relative to the wild type. Taken together, this study provides direct evidence that mutual regulation mechanisms exist between the CK and ABA metabolism and signals underlying different processes regulating plant adaptation to stressors as well as plant growth and development.

594 citations



Journal ArticleDOI
TL;DR: Drug nanocrystals are the latest, broadly introduced nanoparticulate carrier to the pharmaceutical market from the year 2000 onwards and the effect of size, degradability versus biopersistency and intracellular uptake are discussed, classifying the nanocry crystals in the low/non-risk group.

Journal ArticleDOI
TL;DR: The findings support a central function of cytokinin in regulating reproductive meristems and highlight the relevance of sink strength in determining yield in Arabidopsis thaliana.
Abstract: The size and activity of the shoot apical meristem is regulated by transcription factors and low molecular mass signals, including the plant hormone cytokinin. The cytokinin status of the meristem depends on different factors, including metabolic degradation of the hormone, which is catalyzed by cytokinin oxidase/dehydrogenase (CKX) enzymes. Here, we show that CKX3 and CKX5 regulate the activity of the reproductive meristems of Arabidopsis thaliana. CKX3 is expressed in the central WUSCHEL (WUS) domain, while CKX5 shows a broader meristematic expression. ckx3 ckx5 double mutants form larger inflorescence and floral meristems. An increased size of the WUS domain and enhanced primordia formation indicate a dual function for cytokinin in defining the stem cell niche and delaying cellular differentiation. Consistent with this, mutation of a negative regulator gene of cytokinin signaling, ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN 6, which is expressed at the meristem flanks, caused a further delay of differentiation. Terminal cellular differentiation was also retarded in ckx3 ckx5 flowers, which formed more cells and became larger, corroborating the role of cytokinin in regulating flower organ size. Furthermore, higher activity of the ckx3 ckx5 placenta tissue established supernumerary ovules leading to an increased seed set per silique. Together, the results underpin the important role of cytokinin in reproductive development. The increased cytokinin content caused an ~55% increase in seed yield, highlighting the relevance of sink strength as a yield factor.

Journal ArticleDOI
01 Feb 2011-Ecology
TL;DR: It is demonstrated theoretically and empirically that host-specific soil microbes can be major determinants of the diversity-productivity relationship in grasslands using an analytical model and a series of experiments.
Abstract: Ecosystem productivity commonly increases asymptotically with plant species diversity, and determining the mechanisms responsible for this well-known pattern is essential to predict potential changes in ecosystem productivity with ongoing species loss. Previous studies attributed the asymptotic diversity-productivity pattern to plant competition and differential resource use (e.g., niche complementarity). Using an analytical model and a series of experiments, we demonstrate theoretically and empirically that host-specific soil microbes can be major determinants of the diversity-productivity relationship in grasslands. In the presence of soil microbes, plant disease decreased with increasing diversity, and productivity increased nearly 500%, primarily because of the strong effect of density-dependent disease on productivity at low diversity. Correspondingly, disease was higher in plants grown in conspecific-trained soils than heterospecific-trained soils (demonstrating host-specificity), and productivity increased and host-specific disease decreased with increasing community diversity, suggesting that disease was the primary cause of reduced productivity in species- poor treatments. In sterilized, microbe-free soils, the increase in productivity with increasing plant species number was markedly lower than the increase measured in the presence of soil microbes, suggesting that niche complementarity was a weaker determinant of the diversity- productivity relationship. Our results demonstrate that soil microbes play an integral role as determinants of the diversity-productivity relationship.

Journal ArticleDOI
TL;DR: The theoretical developments and research evidence for the self-regulation framework explain the cognitive mechanisms of behavior change and adherence to treatment in the rehabilitation setting.
Abstract: Objective: The present article presents an overview of theoretical constructs and mechanisms of health behavior change that have been found useful in research on people with chronic illness and disability. A self-regulation framework (Health Action Process Approach) serves as a backdrop, making a distinction between goal setting and goal pursuit. Risk perception, outcome expectancies, and task self-efficacy are seen as predisposing factors in the goal-setting (motivational) phase, whereas planning, action control, and maintenance/recovery self-efficacy are regarded as being influential in the subsequent goal-pursuit (volitional) phase. The first phase leads to forming an intention, and the second to actual behavior change. Such a mediator model serves to explain social– cognitive processes in health behavior change. By adding a second layer, a moderator model is provided in which three stages are distinguished to segment the audience for tailored interventions. Identifying persons as preintenders, intenders, or actors offers an opportunity to match theorybased treatments to specific target groups. Numerous research and assessment examples, especially within the physical activity domain, serve to illustrate the application of the model to rehabilitation settings and health promotion for people with chronic illness or disability. Conclusions/Implications: The theoretical developments and research evidence for the self-regulation framework explain the cognitive mechanisms of behavior change and adherence to treatment in the rehabilitation setting.

Journal ArticleDOI
TL;DR: The ArcMap toolbar CraterTools developed in this context significantly helps to improve and simplify the crater size-frequency (CSF) measurement process as discussed by the authors, which can also be theoretically transferred to every Geographic Information System (GIS) capable of working with different map projections.

Journal ArticleDOI
Abstract: Unrealistic optimism is a pervasive human trait that influences domains ranging from personal relationships to politics and finance. How people maintain unrealistic optimism, despite frequently encountering information that challenges those biased beliefs, is unknown. We examined this question and found a marked asymmetry in belief updating. Participants updated their beliefs more in response to information that was better than expected than to information that was worse. This selectivity was mediated by a relative failure to code for errors that should reduce optimism. Distinct regions of the prefrontal cortex tracked estimation errors when those called for positive update, both in individuals who scored high and low on trait optimism. However, highly optimistic individuals exhibited reduced tracking of estimation errors that called for negative update in right inferior prefrontal gyrus. These findings indicate that optimism is tied to a selective update failure and diminished neural coding of undesirable information regarding the future.

Journal ArticleDOI
TL;DR: In this article, the authors examine the state of the art in comparative and international corporate governance by identifying the key research questions, main concepts, and paradigms of explanations of cross-country diversity in corporate governance.
Abstract: In this article, we examine the state of the art in comparative and international corporate governance by identifying the key research questions, main concepts, and paradigms of explanations of cross-country diversity in corporate governance. First, we discuss the multiple definitions of corporate governance across disciplines and explore how this multi-dimensional nature of corporate governance posses challenges when making cross-national comparisons. Second, we review existing comparative research on corporate governance and highlight some of the main characteristics of comparative analysis. Third, we analyze how comparative corporate governance has been understood from four different scholarly perspectives: economics and management, culture and sociology, legal, and political paradigms. We conclude from this third section that future research should make an effort to better integrate cross-disciplinary paradigms. Fourth, we investigate what insights these four perspectives bring to better understand change and stability in two particular governance dimensions: corporate ownership and the role of labor in comparative corporate governance. Finally, we conclude the article with some forward looking suggestions regarding (1) how different perspectives of corporate governance can be more effectively integrated by adopting case-based, historical and actor-centered forms of institutional explanations and by (2) discussing the current U.S. corporate governance system, frequently seen as the "best practice" model.

Journal ArticleDOI
TL;DR: PluriTest is reported, a robust open-access bioinformatic assay of pluripotency in human cells based on their gene expression profiles that allows for indirect methods such as differentiation into teratomas in immunodeficient mice.
Abstract: Pluripotent stem cells (PSCs) are defined by their potential to generate all cell types of an organism. The standard assay for pluripotency of mouse PSCs is cell transmission through the germline, but for human PSCs researchers depend on indirect methods such as differentiation into teratomas in immunodeficient mice. Here we report PluriTest, a robust open-access bioinformatic assay of pluripotency in human cells based on their gene expression profiles.

Journal ArticleDOI
TL;DR: Results suggest that EEG recordings during normal vision are feasible and useful to consolidate findings from EEG and eye-tracking studies, and 4 technical and data-analytical problems that need to be addressed when FRPs are recorded in free-viewing situations are reviewed.
Abstract: Brain-electric correlates of reading have traditionally been studied with word-by-word presentation, a condition that eliminates important aspects of the normal reading process and precludes direct comparisons between neural activity and oculomotor behavior. In the present study, we investigated effects of word predictability on eye movements (EM) and fixation-related brain potentials (FRPs) during natural sentence reading. Electroencephalogram (EEG) and EM (via video-based eye tracking) were recorded simultaneously while subjects read heterogeneous German sentences, moving their eyes freely over the text. FRPs were time-locked to first-pass reading fixations and analyzed according to the cloze probability of the currently fixated word. We replicated robust effects of word predictability on EMs and the N400 component in FRPs. The data were then used to model the relation among fixation duration, gaze duration, and N400 amplitude, and to trace the time course of EEG effects relative to effects in EM behavior. In an extended Methodological Discussion section, we review 4 technical and data-analytical problems that need to be addressed when FRPs are recorded in free-viewing situations (such as reading, visual search, or scene perception) and propose solutions. Results suggest that EEG recordings during normal vision are feasible and useful to consolidate findings from EEG and eye-tracking studies.


Journal ArticleDOI
TL;DR: It is demonstrated that a single dominant gene could regulate a complex trait, root growth, and cytokinin regulates root growth in a largely organ-autonomous fashion that is consistent with its dual role as a hormone with both paracrine and long-distance activities.
Abstract: Optimizing root system architecture can overcome yield limitations in crop plants caused by water or nutrient shortages. Classic breeding approaches are difficult because the trait is governed by many genes and is difficult to score. We generated transgenic Arabidopsis thaliana and tobacco (Nicotiana tabacum) plants with enhanced root-specific degradation of the hormone cytokinin, a negative regulator of root growth. These transgenic plants form a larger root system, whereas growth and development of the shoot are similar. Elongation of the primary root, root branching, and root biomass formation were increased by up to 60% in transgenic lines, increasing the root-to-shoot ratio. We thus demonstrated that a single dominant gene could regulate a complex trait, root growth. Moreover, we showed that cytokinin regulates root growth in a largely organ-autonomous fashion that is consistent with its dual role as a hormone with both paracrine and long-distance activities. Transgenic plants had a higher survival rate after severe drought treatment. The accumulation of several elements, including S, P, Mn, Mg, Zn, as well as Cd from a contaminated soil, was significantly increased in shoots. Under conditions of sulfur or magnesium deficiency, leaf chlorophyll content was less affected in transgenic plants, demonstrating the physiological relevance of shoot element accumulation. Our approach might contribute to improve drought tolerance, nutrient efficiency, and nutrient content of crop plants.

Journal ArticleDOI
TL;DR: The lipid nanoparticles were developed as alternative to traditional carriers such as polymeric nanoparticles and liposomes and entered first the cosmetic market, and a pharmaceutical perspective for the future is given.
Abstract: In 1990, the lipid nanoparticles were invented in the laboratories, the first patent filings took place in 1991. The lipid nanoparticles were developed as alternative to traditional carriers such as polymeric nanoparticles and liposomes. After 20 years of lipid nanoparticles, the present state of development is reviewed - academic progress but also the development state of pharmaceutical products for the benefit of patients. Meanwhile many research groups are active worldwide, their results are reviewed which cover many different administration routes: dermal and mucosal, oral, intravenous/ parenteral, pulmonary but also ocular. The lipid nanoparticles are also used for peptide/protein delivery, in gene therapy and various miscellaneous applications (e.g. vaccines). The questions of large scale production ability, accepted regulatory status of excipients, and - important for the public perception - lack of nanotoxicity are discussed, important pre-requisites for the use of each nanocarrier in products. Identical to the liposomes, the lipid nanoparticles entered first the cosmetic market, product examples are presented. Presently the pharmaceutical product development focuses on products for unmet needs and on niche products with lower development costs (e.g. ocular delivery), which can be realized also by smaller companies. A pharmaceutical perspective for the future is given, but also outlined the opportunities for non-pharmaceutical use, e.g. in nutraceuticals.

Journal ArticleDOI
TL;DR: In this paper, the atomic structure of the potential photovoltaic materials Cu 2 ZnSnS 4 (CZTS) and CZTSe 4 was discussed on the basis of a structural analysis of neutron powder diffraction data refined by the Rietveld analysis.

Journal ArticleDOI
20 May 2011-Science
TL;DR: Magnetic and superconducting interactions couple electrons together to form complex states of matter and, at the atomic scale, both types of interactions can coexist and compete to influence the ground state of a localized magnetic moment.
Abstract: Magnetic and superconducting interactions couple electrons together to form complex states of matter. We show that, at the atomic scale, both types of interactions can coexist and compete to influence the ground state of a localized magnetic moment. Local spectroscopy at 4.5 kelvin shows that the spin-1 system formed by manganese-phthalocyanine (MnPc) adsorbed on Pb(111) can lie in two different magnetic ground states. These are determined by the balance between Kondo screening and superconducting pair-breaking interactions. Both ground states alternate at nanometer length scales to form a Moire-like superstructure. The quantum phase transition connecting the two (singlet and doublet) ground states is thus tuned by small changes in the molecule-lead interaction.

Journal ArticleDOI
TL;DR: It is suggested that the interacting transport processes for SCFA, urea, and ammonia represent evolutionary adaptations of ruminants to actively coordinate energy fermentation, protein assimilation, and pH regulation in the rumen.
Abstract: Highly fermentable diets are rapidly converted to organic acids [i.e., short-chain fatty acids (SCFA) and lactic acid] within the rumen. The resulting release of protons can constitute a challenge to the ruminal ecosystem and animal health. Health disturbances, resulting from acidogenic diets, are classified as subacute and acute acidosis based on the degree of ruminal pH depression. Although increased acid production is a nutritionally desired effect of increased concentrate feeding, the accumulation of protons in the rumen is not. Consequently, mechanisms of proton removal and their quantitative importance are of major interest. Saliva buffers (i.e., bicarbonate, phosphate) have long been identified as important mechanisms for ruminal proton removal. An even larger proportion of protons appears to be removed from the rumen by SCFA absorption across the ruminal epithelium, making efficiency of SCFA absorption a key determinant for the individual susceptibility to subacute ruminal acidosis. Proceeding initially from a model of exclusively diffusional absorption of fermentation acids, several protein-dependent mechanisms have been discovered over the last 2 decades. Although the molecular identity of these proteins is mostly uncertain, apical acetate absorption is mediated, to a major degree, via acetate-bicarbonate exchange in addition to another nitrate-sensitive, bicarbonate-independent transport mechanism and lipophilic diffusion. Propionate and butyrate also show partially bicarbonate-dependent transport modes. Basolateral efflux of SCFA and their metabolites has to be mediated primarily by proteins and probably involves the monocarboxylate transporter (MCT1) and anion channels. Although the ruminal epithelium removes a large fraction of protons from the rumen, it also recycles protons to the rumen via apical sodium-proton exchanger, NHE. The latter is stimulated by ruminal SCFA absorption and salivary Na(+) secretion and protects epithelial integrity. Finally, SCFA absorption also accelerates urea transport into the rumen, which via ammonium recycling, may remove protons from rumen to the blood. Ammonium absorption into the blood is also stimulated by luminal SCFA. It is suggested that the interacting transport processes for SCFA, urea, and ammonia represent evolutionary adaptations of ruminants to actively coordinate energy fermentation, protein assimilation, and pH regulation in the rumen.

Journal ArticleDOI
TL;DR: In this article, the feasibility of the black soldier fly larvae to digest and degrade mixed municipal organic waste in a medium-scale field experiment in Costa Rica, and explored the benefits and limitations of this technology.
Abstract: Valorisation of municipal organic waste through larval feeding activity of the black soldier fly, Hermetia illucens, constitutes a potential benefit, especially for low and middle-income countries. Besides waste reduction and stabilisation, the product in form of the last larval stage, the so-called prepupae, offers a valuable additive in animal feed, opening new economic niches for small entrepreneurs in developing countries. We have therefore evaluated the feasibility of the black soldier fly larvae to digest and degrade mixed municipal organic waste in a medium-scale field experiment in Costa Rica, and explored the benefits and limitations of this technology. We achieved an average prepupae production of 252 g/m2/day (wet weight) under favourable conditions. Waste reduction ranged from 65.5 to 78.9% depending on the daily amount of waste added to the experimental unit and presence/absence of a drainage system. Three factors strongly influenced larval yield and waste reduction capacity: (1) high larval mortality due to elevated zinc concentrations in the waste material and anaerobic conditions in the experimental trays; (2) lack of fertile eggs due to zinc poisoning, and (3) limited access to food from stagnating liquid in the experimental trays. This study confirmed the great potential of this fly as a waste manager in low and middle-income countries, but also identified knowledge gaps pertaining to biological larvae requirements (egg hatching rate, moisture tolerance, …) and process design (drainage, rearing facilities, …) to be tackled in future research.

Journal ArticleDOI
TL;DR: In this article, the authors examined measurement invariance and age-related robustness of a short 15-item Big Five Inventory (BFI-S) of personality dimensions, which is well suited for applications in large-scale multidisciplinary surveys.
Abstract: We examined measurement invariance and age-related robustness of a short 15-item Big Five Inventory (BFI–S) of personality dimensions, which is well suited for applications in large-scale multidisciplinary surveys. The BFI–S was assessed in three different interviewing conditions: computer-assisted or paper-assisted face-to-face interviewing, computer-assisted telephone interviewing, and a self-administered questionnaire. Randomized probability samples from a large-scale German panel survey and a related probability telephone study were used in order to test method effects on self-report measures of personality characteristics across early, middle, and late adulthood. Exploratory structural equation modeling was used in order to test for measurement invariance of the five-factor model of personality trait domains across different assessment methods. For the short inventory, findings suggest strong robustness of self-report measures of personality dimensions among young and middle-aged adults. In old age, telephone interviewing was associated with greater distortions in reliable personality assessment. It is concluded that the greater mental workload of telephone interviewing limits the reliability of self-report personality assessment. Face-to-face surveys and self-administrated questionnaire completion are clearly better suited than phone surveys when personality traits in age-heterogeneous samples are assessed.

Journal ArticleDOI
TL;DR: The identification of SLAH3 as the nitrate-, calcium-, and ABA-sensitive guard cell anion channel provides insights into the relationship among stomatal response to drought, signaling by nitrate, and nitrate metabolism.
Abstract: S-type anion channels are direct targets of abscisic acid (ABA) signaling and contribute to chloride and nitrate release from guard cells, which in turn initiates stomatal closure. SLAC1 was the first component of the guard cell S-type anion channel identified. However, we found that guard cells of Arabidopsis SLAC1 mutants exhibited nitrate conductance. SLAH3 (SLAC1 homolog 3) was also present in guard cells, and coexpression of SLAH3 with the calcium ion (Ca2+)-dependent kinase CPK21 in Xenopus oocytes mediated nitrate-induced anion currents. Nitrate, calcium, and phosphorylation regulated SLAH3 activity. CPK21-dependent SLAH3 phosphorylation and activation were blocked by ABI1, a PP2C-type protein phosphatase that is inhibited by ABA and inhibits the ABA signaling pathway in guard cells. We reconstituted the ABA-stimulated phosphorylation of the SLAH3 amino-terminal domain by CPK21 in vitro by including the ABA receptor-phosphatase complex RCAR1-ABI1 in the reactions. We propose that ABA perception by the complex consisting of ABA receptors of the RCAR/PYR/PYL family and ABI1 releases CPK21 from inhibition by ABI1, and then CPK21 is further activated by an increase in the cytosolic Ca2+ concentration, leading to its phosphorylation of SLAH3. Thus, the identification of SLAH3 as the nitrate-, calcium-, and ABA-sensitive guard cell anion channel provides insights into the relationship among stomatal response to drought, signaling by nitrate, and nitrate metabolism.

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TL;DR: In this article, a photoactivated adenylyl cyclase (bPAC) was identified in the genome of the bacterium Beggiatoa and showed cyclase activity that was low in darkness but increased 300-fold in the light.

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TL;DR: Based on size, stability and release/permeation data, and considering the chemical protection of the lutein prior to its absorption into the skin, the lipid nanoparticles are potential dermal nanocarriers for lutenin.