Showing papers by "Free University of Berlin published in 2012"
TL;DR: A detailed analysis of the Raman spectra of graphene containing different type of defects is presented, finding that the intensity ratio of the D and D' peak is maximum for sp(3)-defects, it decreases for vacancy-like defects, and it reaches a minimum for boundaries in graphite.
Abstract: Raman spectroscopy is able to probe disorder in graphene through defect-activated peaks. It is of great interest to link these features to the nature of disorder. Here we present a detailed analysis of the Raman spectra of graphene containing different type of defects. We found that the intensity ratio of the D and D′ peak is maximum (∼13) for sp3-defects, it decreases for vacancy-like defects (∼7), and it reaches a minimum for boundaries in graphite (∼3.5). This makes Raman Spectroscopy a powerful tool to fully characterize graphene.
1,716 citations
TL;DR: It is established that the mean dissipated heat saturates at the Landauer bound in the limit of long erasure cycles, demonstrating the intimate link between information theory and thermodynamics and highlighting the ultimate physical limit of irreversible computation.
Abstract: In 1961, Rolf Landauer argued that the erasure of information is a dissipative process. A minimal quantity of heat, proportional to the thermal energy and called the Landauer bound, is necessarily produced when a classical bit of information is deleted. A direct consequence of this logically irreversible transformation is that the entropy of the environment increases by a finite amount. Despite its fundamental importance for information theory and computer science, the erasure principle has not been verified experimentally so far, the main obstacle being the difficulty of doing single-particle experiments in the low-dissipation regime. Here we experimentally show the existence of the Landauer bound in a generic model of a one-bit memory. Using a system of a single colloidal particle trapped in a modulated double-well potential, we establish that the mean dissipated heat saturates at the Landauer bound in the limit of long erasure cycles. This result demonstrates the intimate link between information theory and thermodynamics. It further highlights the ultimate physical limit of irreversible computation.
1,019 citations
TL;DR: This review gives a brief overview about some types of stimuli-responsive nanocarriers with the main focus on organic polymer-based systems.
963 citations
TL;DR: The findings show that life events have very different effects on affective and cognitive well-being and that for most events the effects of life events on cognitive well -being are stronger and more consistent across samples.
Abstract: Previous research has shown that major life events can have short- and long-term effects on subjective well-being (SWB). The present meta-analysis examines (a) whether life events have different effects on affective and cognitive well-being and (b) how the rate of adaptation varies across different life events. Longitudinal data from 188 publications (313 samples, N = 65,911) were integrated to describe the reaction and adaptation to 4 family events (marriage, divorce, bereavement, childbirth) and 4 work events (unemployment, reemployment, retirement, relocation/migration). The findings show that life events have very different effects on affective and cognitive well-being and that for most events the effects of life events on cognitive well-being are stronger and more consistent across samples. Different life events differ in their effects on SWB, but these effects are not a function of the alleged desirability of events. The results are discussed with respect to their theoretical implications, and recommendations for future studies on adaptation are given.
956 citations
TL;DR: In this article, a study combining an experimental approach for monitoring the dynamics of strongly correlated cold atoms with theoretical analysis provides quantitative insights into the problem of quantum many-body systems relax from an initial non-equilibrium state.
Abstract: How quantum many-body systems relax from an initial non-equilibrium state is one of the outstanding problems in quantum statistical physics. A study combining an experimental approach for monitoring the dynamics of strongly correlated cold atoms with theoretical analysis now provides quantitative insights into the problem.
922 citations
TL;DR: The lack of knowledge on microplastic in soil is surprising given that the occurrence of larger plastic fragments in soils per se is nothing new, and has in fact been a trait used to describe urban soils or Technosols.
Abstract: W live in a “plastic age” with more than 240 million tons of plastic used annually, the majority of which for disposable use. Due to limited recovery of discarded materials and its durability, plastic debris is accumulating in the environment. Recently, research on environmental impacts of plastic has acquired a new dimension through the discovery and study of microplastic, particles often defined as smaller than 1 mm, but that are often in the range of several micrometers. These microplastics present a new set of issues, because of two main reasons: (i) they are small enough to be taken up by biota and thus can accumulate in the food chain; and (ii) they can sorb pollutants on their surfaces, thus enriching them on these particles. The occurrence of microplastic materials has been studied almost exclusively in marine environments and, related to this, on shorelines. Yet the terrestrial landmasses are conspicuously empty on maps of global microplastic distribution: they have simply not been studied. Why have microplastics not been studied in soils and terrestrial systems? First, there is a separation between marine and terrestrial ecological research such that ideas do not easily propagate from one domain to the other. Also important is the comparative ease with which microplastic filaments can be extracted and quantified from water. This is not so straightforward for the complex organo−mineral soil matrix. Also, there is a pattern of accumulation along shorelines, which has no parallel in terrestrial systems. Finally, aquatic environments harbor many filter-feeders, a mode of nutrition that will make organisms particularly susceptible to accumulating harmful particles from a large volume of the environment. Still, our lack of knowledge on microplastic in soil is surprising given that the occurrence of larger plastic fragments in soils per se is nothing new, and has in fact been a trait used to describe urban soils or Technosols. Microplastic can occur in the environment either as primary or secondary microplastics. Particles can enter the environment directly as primary microplastic: microplastics are manufactured for a number of purposes, such as for use as industrial abrasives or for cosmetics products. In contrast, secondary microplastics are produced through the environmental degradation of larger-sized pieces. Secondary microplastics could result from abrasion of plastic debris at soil surfaces (where UV light could render the material brittle) or inside the soil profile. In agricultural fields where plastic mulching is practiced, an abundant source of plastic material would be available; in other cases, incidental plastic debris would be the starting material. Curiously, even washing machines can produce secondary microplastic fibers; via water treatment plants these could end up on agricultural fields. It is tempting to speculate that tumble driers could also be a possible source of microplastics. Very small particles or fibers could be spread further by becoming air-borne (for example from landfills, or other surface deposits) and then enter terrestrial systems and the soil through atmospheric deposition. Geophagous soil fauna, most notably earthworms, could contribute to secondary microplastic formation: in their gizzard, they may grind up brittle plastic debris that they ingest into microplastic. Anecic earthworms, such that produce vertical burrows but feed near the soil surface, could even additionally promote incorporation of surface-deposited plastic pieces into the soil. Other soil mesofauna (such as collembola or mites) may also contribute to this breakdown by incidentally scraping or chewing off pieces of plastic. Also digging mammals, such as gophers or moles, could conceivably contribute to abrasion and incorporation into the soil. The actual direct, quantitative evidence of microplastic occurrence in soil is very thin. One study found synthetic fibers in several soils in the U.S. to which organic waste material had been applied. Others have found spectra in their soil organic matter analyses that are consistent with the presence of different types of plastic, but natural sources could not be completely ruled out. Many studies have just reported the presence of plastic in soil, but have not quantified the amount, nor described the size of the particles. Given that microplastic likely is in our soils, can it have adverse effects? Obviously, soil is quite different from oceans, but soil also contains many features of an aquatic system: many biota are essentially aquatic, thriving in a thin film of water covering soil surfaces. Thus, some of the same principles apply. Of course the soil also has its filter feeders, active on the water films on soil surfaces, like ciliates and rotifers; these similarly
916 citations
TL;DR: Partizipative qualitative Forschung (PDF) as mentioned in this paper is a partizipativer methodik approach to qualitative research, in which the goal is to find a solution to a specific problem.
Abstract: Dieser Beitrag soll in die FQS-Schwerpunktausgabe "Partizipative qualitative Forschung" einfuhren. Partizipative Forschungsstrategien finden in neuerer Zeit wieder groseres Interesse. Die Aufsatze aus unterschiedlichen Disziplinen befassen sich auf dem Hintergrund von konkreten empirischen Forschungsprojekten mit verschiedenen konzeptionellen Uberlegungen und methodischen Herangehensweisen. Uber die Lekture dieser Beitrage und in Auseinandersetzung mit den Forderungen der Autor/innen sind wir dazu angeregt worden, auf jene Bereiche besonders einzugehen, in denen unserer Ansicht nach weitergearbeitet werden sollte. Dies betrifft Grundlagen partizipativer Forschung wie demokratietheoretische Uberlegungen, das Konzept des "sicheren Raums", Fragen der Partizipation oder der Ethik, aber auch forschungspraktische Fragen zur Rolle und zu den Aufgaben der verschiedenen Teilnehmenden, zu besonderen methodischen Herangehensweisen bis zur Frage der Gutekriterien, die hier als Rechtfertigungsargumente verstanden werden. Damit soll zu einer breiten Diskussion angeregt werden, die nicht nur auf den engeren Bereich partizipativer Forschung bezogen sein sollte. Da partizipative Methodik manche Fragen nach Erkenntnis und Forschung radikal stellt, birgt sie in sich auch die Chance, auf bisher vernachlassigte Bereiche in der qualitativen Methodik hinzuweisen und ihre weitere Entwicklung anzuregen. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1201302
898 citations
TL;DR: In a systematic review of scaffold architectures, the underlying effects and control options will be demonstrated, and suggestions will be given for designing effective multivalent binding systems, as well as for polyvalent therapeutics.
Abstract: Multivalent interactions can be applied universally for a targeted strengthening of an interaction between different interfaces or molecules. The binding partners form cooperative, multiple receptor-ligand interactions that are based on individually weak, noncovalent bonds and are thus generally reversible. Hence, multi- and polyvalent interactions play a decisive role in biological systems for recognition, adhesion, and signal processes. The scientific and practical realization of this principle will be demonstrated by the development of simple artificial and theoretical models, from natural systems to functional, application-oriented systems. In a systematic review of scaffold architectures, the underlying effects and control options will be demonstrated, and suggestions will be given for designing effective multivalent binding systems, as well as for polyvalent therapeutics.
820 citations
Posted Content•
TL;DR: Corporate Social Responsibility (CSR) has become a pervasive topic in the business literature, but has largely neglected the role of institutions as discussed by the authors, which suggests going beyond grounding CSR in the voluntary behaviour of companies, and understanding the larger historical and political determinants of whether and in what forms corporations take on social responsibilities.
Abstract: Corporate Social Responsibility (CSR) has become a pervasive topic in the business literature, but has largely neglected the role of institutions. This introductory article to the Special Issue of Socio-Economic Review examines the potential contributions of institutional theory to understanding CSR as a mode of governance. This perspective suggests going beyond grounding CSR in the voluntary behaviour of companies, and understanding the larger historical and political determinants of whether and in what forms corporations take on social responsibilities. Historically, the prevailing notion of CSR emerged through the defeat of more institutionalized forms of social solidarity in liberal market economies. Meanwhile, CSR is more tightly linked to formal institutions of stakeholder participation or state intervention in other advanced economies. The tensions between business-driven and multi-stakeholder forms of CSR extend to the transnational level, where the form and meaning of CSR remain highly contested. CSR research and practice thus rest on a basic paradox between a liberal notion of voluntary engagement and a contrary implication of socially binding responsibilities. Institutional theory seems to be a promising avenue to explore how the boundaries between business and society are constructed in different ways, and improve our understanding of the effectiveness of CSR within the wider institutional field of economic governance.
717 citations
TL;DR: In this article, the potential contributions of institutional theory to understand corporate social responsibility as a mode of governance are examined. But the focus is on the voluntary behavior of companies and not on the larger historical and political determinants of whether and in what forms corporations take on social responsibilities.
Abstract: *Corporate Social Responsibility (CSR) has become a pervasive topic in the business literature, but has largely neglected the role of institutions. This introductory article to the Special Issue of Socio-Economic Review examines the potential contributions of institutional theory to understanding CSR as a mode of governance. This perspective suggests going beyond grounding CSR in the voluntary behaviour of companies, and understanding the larger historical and political determinants of whether and in what forms corporations take on social responsibilities. Historically, the prevailing notion of CSR emerged through the defeat of more institutionalized forms of social solidarity in liberal market economies. Meanwhile, CSR is more tightly linked to formal institutions of stakeholder participation or state intervention in other advanced economies. The tensions between business-driven and multi-stakeholder forms of CSR extend to the transnational level, where the form and meaning of CSR remain highly contested. CSR research and practice thus rest on a basic paradox between a liberal notion of voluntary engagement and a contrary implication of socially binding responsibilities. Institutional theory seems to be a promising avenue to explore how the boundaries between business and society are constructed in different ways, and improve our understanding of the effectiveness of CSR within the wider institutional field of economic governance.
660 citations
TL;DR: The opinion that animal ESBL-producing E. coli is a major source of human infections is oversimplified, and neglects a highly complex scenario.
Max Planck Society1, Free University of Berlin2, University of Colorado Boulder3, University of Oxford4, Royal Berkshire NHS Foundation Trust5, University of Ioannina6, Harvard University7, Mayo Clinic8, University of Miami9, University of Tübingen10, German Center for Neurodegenerative Diseases11, Boston University12, Emory University13, University of British Columbia14, Indiana University15, Wadsworth Center16, University College London17, VU University Amsterdam18, University of Lübeck19, University of Chicago20, University of Toulouse21, Centre national de la recherche scientifique22, National Institutes of Health23, Kobe University24, deCODE genetics25, University of Washington26, University of Münster27, Centers for Disease Control and Prevention28, University of Mainz29
TL;DR: This study provides an exhaustive and up-to-date summary of the status of PD genetics research that can be readily scaled to include the results of future large-scale genetics projects, including next-generation sequencing studies.
Abstract: More than 800 published genetic association studies have implicated dozens of potential risk loci in Parkinson’s disease (PD). To facilitate the interpretation of these findings, we have created a dedicated online resource, PDGene, that comprehensively collects and meta-analyzes all published studies in the field. A systematic literature screen of ,27,000 articles yielded 828 eligible articles from which relevant data were extracted. In addition, individual-level data from three publicly available genome-wide association studies (GWAS) were obtained and subjected to genotype imputation and analysis. Overall, we performed meta-analyses on more than seven million polymorphisms originating either from GWAS datasets and/or from smaller scale PD association studies. Metaanalyses on 147 SNPs were supplemented by unpublished GWAS data from up to 16,452 PD cases and 48,810 controls. Eleven loci showed genome-wide significant (P,5610 28 ) association with disease risk: BST1, CCDC62/HIP1R, DGKQ/GAK, GBA, LRRK2, MAPT, MCCC1/LAMP3 ,P ARK16,SNCA, STK39 ,a ndSYT11/RAB25. In addition, we identified novel evidence for genome-wide significant association with a polymorphism in ITGA8 (rs7077361, OR 0.88, P=1.3610 28 ). All meta-analysis results are freely available on a dedicated online database (www.pdgene.org), which is cross-linked with a customized track on the UCSC Genome Browser. Our study provides an exhaustive and up-to-date summary of the status of PD genetics research that can be readily scaled to include the results of future large-scale genetics projects, including next-generation sequencing studies.
TL;DR: Graphene bubbles are used to study the Raman spectrum of graphene under biaxial (e.g., isotropic) strain and the Gruneisen parameters are in excellent agreement with the theoretical values.
Abstract: We use graphene bubbles to study the Raman spectrum of graphene under biaxial (e.g., isotropic) strain. Our Gruneisen parameters are in excellent agreement with the theoretical values. Discrepancy in the previously reported values is attributed to the interaction of graphene with the substrate. Bilayer balloons (intentionally pressurized membranes) have been used to avoid the effect of the substrate and to study the dependence of strain on the interlayer interactions.
University of Geneva1, Centre national de la recherche scientifique2, University of Saskatchewan3, Natural History Museum4, New York State Department of Health5, Charles University in Prague6, Kaiserslautern University of Technology7, University of Greifswald8, Dalhousie University9, Free University of Berlin10, Academy of Sciences of the Czech Republic11, University of British Columbia12, Sewanee: The University of the South13, Saint Petersburg State University14, Royal Botanic Garden Edinburgh15, University of Cologne16, Uppsala University17, University of New Brunswick18, Halifax19, National Institutes of Health20, University of Giessen21, National Museum of Natural History22
TL;DR: A group of protist experts proposes a two-step DNA barcoding approach, comprising a universal eukaryotic pre-barcode followed by group-specific barcodes, to unveil the hidden biodiversity of microbial Eukaryotes.
Abstract: Animals, plants, and fungi—the three traditional kingdoms of multicellular eukaryotic life—make up almost all of the visible biosphere, and they account for the majority of catalogued species on Earth [1]. The remaining eukaryotes have been assembled for convenience into the protists, a group composed of many diverse lineages, single-celled for the most part, that diverged after Archaea and Bacteria evolved but before plants, animals, or fungi appeared on Earth. Given their single-celled nature, discovering and describing new species has been difficult, and many protistan lineages contain a relatively small number of formally described species (Figure 1A), despite the critical importance of several groups as pathogens, environmental quality indicators, and markers of past environmental changes. It would seem natural to apply molecular techniques such as DNA barcoding to the taxonomy of protists to compensate for the lack of diagnostic morphological features, but this has been hampered by the extreme diversity within the group. The genetic divergence observed between and within major protistan groups greatly exceeds that found in each of the three multicellular kingdoms. No single set of molecular markers has been identified that will work in all lineages, but an international working group is now close to a solution. A universal DNA barcode for protists coupled with group-specific barcodes will enable an explosion of taxonomic research that will catalyze diverse applications.
TL;DR: It is found that skin blood volume strongly depends on the cognitive state and that sources of task-evoked systemic signals in fNIRS are co-localized with veins draining the scalp, and it is concluded that the physiological origin of the systemic artefact is a task- Evoked sympathetic arterial vasoconstriction followed by a decrease in venous volume.
TL;DR: In this article, a method for the retrieval of sun-induced terrestrial chlorophyll fluorescence (F_s) from the Fraunhofer lines resolved by GOSAT-FTS measurements is presented.
TL;DR: This critical review summarizes the current state of the art in the physical-chemical characterization of supramolecular networks and relates this knowledge to that about classical, covalently jointed and crosslinked networks.
Abstract: Supramolecular polymer networks are three-dimensional structures of crosslinked macromolecules connected by transient, non-covalent bonds; they are a fascinating class of soft materials, exhibiting properties such as stimuli-responsiveness, self-healing, and shape-memory. This critical review summarizes the current state of the art in the physical–chemical characterization of supramolecular networks and relates this knowledge to that about classical, covalently jointed and crosslinked networks. We present a separate focus on the formation, the structure, the dynamics, and the mechanics of both permanent chemical and transient supramolecular networks. Particular emphasis is placed on features such as the formation and the effect of network inhomogeneities, the manifestation of the crosslink relaxation dynamics in the macroscopic sample behavior, and the applicability of concepts developed for classical polymer melts, solutions, and networks such as the reptation model and the principle of time–temperature superposition (263 references).
TL;DR: There will emerge that there is a gap between industrial and academic achievements and that this gap will continue to expand unless a change of focus in systems for myoelectric control occurs.
Abstract: In this article, the basic concept of myoelectric control and the state of the art in both industry and academia will be presented. It will emerge that there is a gap between industrial and academic achievements and that this gap will continue to expand unless a change of focus in systems for myoelectric control occurs.
TL;DR: Monte Carlo simulations of the nanoheat engine are performed that demonstrate its feasibility and its ability to operate at a maximum efficiency of 30% under realistic conditions.
Abstract: We propose an experimental scheme to realize a nanoheat engine with a single ion. An Otto cycle may be implemented by confining the ion in a linear Paul trap with tapered geometry and coupling it to engineered laser reservoirs. The quantum efficiency at maximum power is analytically determined in various regimes. Moreover, Monte Carlo simulations of the engine are performed that demonstrate its feasibility and its ability to operate at a maximum efficiency of 30% under realistic conditions.
TL;DR: In this paper, an electrodeposited Mn oxide (MnCat) was reported to catalyzes electrochemical water oxidation at neutral pH at rates that approach the level needed for direct coupling to photoactive materials.
Abstract: In the sustainable production of non-fossil fuels, water oxidation is pivotal. Development of efficient catalysts based on manganese is desirable because this element is earth-abundant, inexpensive, and largely non-toxic. We report an electrodeposited Mn oxide (MnCat) that catalyzes electrochemical water oxidation at neutral pH at rates that approach the level needed for direct coupling to photoactive materials. By choice of the voltage protocol we could switch between electrodeposition of inactive Mn oxides (deposition at constant anodic potentials) and synthesis of the active MnCat (deposition by voltage-cycling protocols). Electron microscopy reveals that the MnCat consists of nanoparticles (100 nm) with complex fine-structure. X-ray spectroscopy reveals that the amorphous MnCat resembles the biological paragon, the water-splitting Mn4Ca complex of photosynthesis, with respect to mean Mn oxidation state (ca. +3.8 in the MnCat) and central structural motifs. Yet the MnCat functions without calcium or other bivalent ions. Comparing the MnCat with electrodeposited Mn oxides inactive in water oxidation, we identify characteristics that likely are crucial for catalytic activity. In both inactive Mn oxides and active ones (MnCat), extensive di-μ-oxo bridging between Mn ions is observed. However in the MnCat, the voltage-cycling protocol resulted in formation of MnIII sites and prevented formation of well-ordered and unreactive MnIVO2. Structure–function relations in Mn-based water-oxidation catalysts and strategies to design catalytically active Mn-based materials are discussed. Knowledge-guided performance optimization of the MnCat could pave the road for its technological use.
TL;DR: A 2.8-million-year record of Arctic climate is developed using a sediment core from a lake in northeastern Russia that was formed more than 3.5 million years ago by a meteorite impact, suggesting strong interhemispheric climate connectivity.
Abstract: The reliability of Arctic climate predictions is currently hampered by insufficient knowledge of natural climate variability in the past. A sediment core from Lake El'gygytgyn in northeastern (NE) ...
TL;DR: Evidence is provided that YAP activates the mammalian target of rapamycin (mTOR), a major regulator of cell growth, and a functional link between Hippo and PI(3)K–mTOR is revealed, providing a molecular basis for the coordination of these two pathways in organ size regulation.
Abstract: Organ development is a complex process governed by the interplay of several signalling pathways that have critical functions in the regulation of cell growth and proliferation. Over the past years, the Hippo pathway has emerged as a key regulator of organ size. Perturbation of this pathway has been shown to play important roles in tumorigenesis. YAP, the main downstream target of the mammalian Hippo pathway, promotes organ growth, yet the underlying molecular mechanism of this regulation remains unclear. Here we provide evidence that YAP activates the mammalian target of rapamycin (mTOR), a major regulator of cell growth. We have identified the tumour suppressor PTEN, an upstream negative regulator of mTOR, as a critical mediator of YAP in mTOR regulation. We demonstrate that YAP downregulates PTEN by inducing miR-29 to inhibit PTEN translation. Last, we show that PI(3)K–mTOR is a pathway modulated by YAP to regulate cell size, tissue growth and hyperplasia. Our studies reveal a functional link between Hippo and PI(3)K–mTOR, providing a molecular basis for the coordination of these two pathways in organ size regulation.
TL;DR: The aim of the present review is to integrate findings from electrophysiological (ERP) and hemodynamic neuroimaging (fMRI) studies in order to provide a better understanding of emotion word processing.
TL;DR: The advanced forms of liposomes and polyethylene glycol (PEG) based nanocarriers, as well as dendritic polymer conjugates will be discussed with particular attention paid to designs, synthetic strategies, and chemical pathways.
Abstract: Nanotechnology has resulted in materials that have greatly improved the effectiveness of drug delivery because of their ability to control matter on the nanoscale. Advanced forms of nanomedicine have been synthesized for better pharmacokinetics to obtain higher efficacy, less systemic toxicity, and better targeting. These criteria have long been the goal in nanomedicine, in particular, for systemic applications in oncological disorders. Now, the “holy grail” in nanomedicine is to design and synthesize new advanced macromolecular nanocarriers and to translate them from lab to clinic. This review describes the current and future perspectives of nanomedicine with particular emphasis on the clinical targets in cancer and inflammation. The advanced forms of liposomes and polyethylene glycol (PEG) based nanocarriers, as well as dendritic polymer conjugates will be discussed with particular attention paid to designs, synthetic strategies, and chemical pathways. In this critical review, we also report on the current status and perspective of dendritic polymer nanoconjugate platforms (e.g. polyamidoamine dendrimers and dendritic polyglycerols) for cellular localization and targeting of specific tissues (192 references).
TL;DR: The three macromolecular crystallography beamlines at the BESSY II storage ring at the Helmholtz-Zentrum Berlin are described.
Abstract: Three macromolecular crystallography (MX) beamlines at the Helmholtz-Zentrum Berlin (HZB) are available for the regional, national and international structural biology user community. The state-of-the-art synchrotron beamlines for MX BL14.1, BL14.2 and BL14.3 are located within the low-β section of the BESSY II electron storage ring. All beamlines are fed from a superconducting 7 T wavelength-shifter insertion device. BL14.1 and BL14.2 are energy tunable in the range 5–16 keV, while BL14.3 is a fixed-energy side station operated at 13.8 keV. All three beamlines are equipped with CCD detectors. BL14.1 and BL14.2 are in regular user operation providing about 200 beam days per year and about 600 user shifts to approximately 50 research groups across Europe. BL14.3 has initially been used as a test facility and was brought into regular user mode operation during the year 2010. BL14.1 has recently been upgraded with a microdiffractometer including a mini-κ goniometer and an automated sample changer. Additional user facilities include office space adjacent to the beamlines, a sample preparation laboratory, a biology laboratory (safety level 1) and high-end computing resources. In this article the instrumentation of the beamlines is described, and a summary of the experimental possibilities of the beamlines and the provided ancillary equipment for the user community is given.
TL;DR: The result generalizes the Gottesman-Knill theorem and provides a way of sampling from the output distribution of a computation or a simulation, including the efficient sampling from an approximate output distribution in the case of sampling imperfections for initial states, gates, or measurements.
Abstract: We show that quantum circuits where the initial state and all the following quantum operations can be represented by positive Wigner functions can be classically efficiently simulated. This is true both for continuous-variable as well as discrete variable systems in odd prime dimensions, two cases which will be treated on entirely the same footing. Noting the fact that Clifford and Gaussian operations preserve the positivity of the Wigner function, our result generalizes the Gottesman-Knill theorem. Our algorithm provides a way of sampling from the output distribution of a computation or a simulation, including the efficient sampling from an approximate output distribution in the case of sampling imperfections for initial states, gates, or measurements. In this sense, this work highlights the role of the positive Wigner function as separating classically efficiently simulable systems from those that are potentially universal for quantum computing and simulation, and it emphasizes the role of negativity of the Wigner function as a computational resource.
University of Cambridge1, NHS Blood and Transplant2, Wellcome Trust Sanger Institute3, Charité4, Katholieke Universiteit Leuven5, European Bioinformatics Institute6, Leiden University Medical Center7, French Institute of Health and Medical Research8, Free University of Berlin9, Maastricht University10, St. Michael's GAA, Sligo11, University of Bristol12
TL;DR: The first human disorder, thrombocytopenia with absent radii (TAR), is described, caused by deficiency in one of the four EJC subunits, and data implicate Y14 insufficiency and, presumably, an EJC defect as the cause of TAR syndrome.
Abstract: The exon-junction complex (EJC) performs essential RNA processing tasks. Here, we describe the first human disorder, thrombocytopenia with absent radii (TAR), caused by deficiency in one of the four EJC subunits. Compound inheritance of a rare null allele and one of two low-frequency SNPs in the regulatory regions of RBM8A, encoding the Y14 subunit of EJC, causes TAR. We found that this inheritance mechanism explained 53 of 55 cases (P < 5 × 10(-228)) of the rare congenital malformation syndrome. Of the 53 cases with this inheritance pattern, 51 carried a submicroscopic deletion of 1q21.1 that has previously been associated with TAR, and two carried a truncation or frameshift null mutation in RBM8A. We show that the two regulatory SNPs result in diminished RBM8A transcription in vitro and that Y14 expression is reduced in platelets from individuals with TAR. Our data implicate Y14 insufficiency and, presumably, an EJC defect as the cause of TAR syndrome.
TL;DR: Honeybees contradict the notion that insect behaviour tends to be relatively inflexible and stereotypical, and have been used to model learning and memory formation, highlighting its utility for neuroscience research, in particular for understanding the basis of cognition.
Abstract: Honeybees contradict the notion that insect behaviour tends to be relatively inflexible and stereotypical. Indeed, they live in colonies and exhibit complex social, navigational and communication behaviours, as well as a relatively rich cognitive repertoire. Because these relatively complex behaviours are controlled by a brain consisting of only 1 million or so neurons, honeybees offer an opportunity to study the relationship between behaviour and cognition in neural networks that are limited in size and complexity. Most recently, the honeybee has been used to model learning and memory formation, highlighting its utility for neuroscience research, in particular for understanding the basis of cognition.
TL;DR: Droplet microfluidic strategies used to fabricate advanced microparticles that are useful structures for the encapsulation and release of actives will enable fabrication of large quantities of novel microparticle structures that have potential uses in controlled drug release applications.
Abstract: We describe droplet microfluidic strategies used to fabricate advanced microparticles that are useful structures for the encapsulation and release of actives; these strategies can be further developed to produce microparticles for advanced drug delivery applications. Microfluidics enables exquisite control in the fabrication of polymer vesicles and thermosensitive microgels from single and higher-order multiple emulsion templates. The strategies used to create the diversity of microparticle structures described in this review, coupled with the scalability of microfluidics, will enable fabrication of large quantities of novel microparticle structures that have potential uses in controlled drug release applications.
TL;DR: This critical review covers the literature dealing with investigations of peptides and proteins containing fluorinated analogues of the canonical amino acids published over the course of the past decade including the late nineties, and focuses on side-chain fluorinated amino acids.
Abstract: Fluorinated analogues of the canonical α-L-amino acids have gained widespread attention as building blocks that may endow peptides and proteins with advantageous biophysical, chemical and biological properties. This critical review covers the literature dealing with investigations of peptides and proteins containing fluorinated analogues of the canonical amino acids published over the course of the past decade including the late nineties. It focuses on side-chain fluorinated amino acids, the carbon backbone of which is identical to their natural analogues. Each class of amino acids—aliphatic, aromatic, charged and polar as well as proline—is presented in a separate section. General effects of fluorine on essential properties such as hydrophobicity, acidity/basicity and conformation of the specific side chains and the impact of these altered properties on stability, folding kinetics and activity of peptides and proteins are discussed (245 references).