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Showing papers by "University of Fribourg published in 2012"


Journal ArticleDOI
TL;DR: This review focuses on the properties and applications of inorganic nanostructured materials and their surface modifications, with good antimicrobial activity, and the role of different NP materials.

2,058 citations


Journal ArticleDOI
TL;DR: Simulations on four real networks show that the proposed semi-local centrality measure can well identify influential nodes and is a tradeoff between the low-relevant degree centrality and other time-consuming measures.
Abstract: Identifying influential nodes that lead to faster and wider spreading in complex networks is of theoretical and practical significance. The degree centrality method is very simple but of little relevance. Global metrics such as betweenness centrality and closeness centrality can better identify influential nodes, but are incapable to be applied in large-scale networks due to the computational complexity. In order to design an effective ranking method, we proposed a semi-local centrality measure as a tradeoff between the low-relevant degree centrality and other time-consuming measures. We use the Susceptible–Infected–Recovered (SIR) model to evaluate the performance by using the spreading rate and the number of infected nodes. Simulations on four real networks show that our method can well identify influential nodes.

898 citations


Journal ArticleDOI
26 Apr 2012-Neuron
TL;DR: This review will highlight the relationship between clocks and metabolism, and describe how cues such as light, food, and reward mediate entrainment of the circadian system.

682 citations


Journal ArticleDOI
TL;DR: By refuting the long-standing universality hypothesis, the data highlight the powerful influence of culture on shaping basic behaviors once considered biologically hardwired and open a unique nature–nurture debate across broad fields from evolutionary psychology and social neuroscience to social networking via digital avatars.
Abstract: Since Darwin’s seminal works, the universality of facial expressions of emotion has remained one of the longest standing debates in the biological and social sciences. Briefly stated, the universality hypothesis claims that all humans communicate six basic internal emotional states (happy, surprise, fear, disgust, anger, and sad) using the same facial movements by virtue of their biological and evolutionary origins [Susskind JM, et al. (2008) Nat Neurosci 11:843–850]. Here, we refute this assumed universality. Using a unique computer graphics platform that combines generative grammars [Chomsky N (1965) MIT Press, Cambridge, MA] with visual perception, we accessed the mind’s eye of 30 Western and Eastern culture individuals and reconstructed their mental representations of the six basic facial expressions of emotion. Cross-cultural comparisons of the mental representations challenge universality on two separate counts. First, whereas Westerners represent each of the six basic emotions with a distinct set of facial movements common to the group, Easterners do not. Second, Easterners represent emotional intensity with distinctive dynamic eye activity. By refuting the long-standing universality hypothesis, our data highlight the powerful influence of culture on shaping basic behaviors once considered biologically hardwired. Consequently, our data open a unique nature–nurture debate across broad fields from evolutionary psychology and social neuroscience to social networking via digital avatars.

616 citations


Journal ArticleDOI
20 Aug 2012-Religion
TL;DR: The Centrality of Religiosity Scale (CRS) is a measure of the centrality, importance or saliency of religious meanings in personality that has been applied yet in more than 100 studies in sociology of religion, psychology of religion and religious studies in 25 countries with in total more than100,000 participants as discussed by the authors.

533 citations


Journal ArticleDOI
TL;DR: The following definitions for a nanoparticle (NP) and a nano-object will be used.
Abstract: Nanotechnology has become a key word of public interest, since people realized the social and economic power of nanotechnology development. Nanotechnology has already become part of our daily life, and it will have an as yet unknown technological impact because it concerns all aspects of human life from novel building materials to electronics, cosmetics, pharmaceutics, and medicine.1 In recent years, engineered nanoparticles started to become the most important components in nanotechnology. The InternationalOrganization for Standardization (ISO) has provided specific definitions in their recent document entitled “Nanotechnologies—Terminology and definitions for nanoobjects—Nanoparticle, nanofibre and nanoplate”. As the basis of this review, the following definitions for a nanoparticle (NP) and a nano-object will be used.

527 citations


Journal ArticleDOI
15 Mar 2012-Nature
TL;DR: It is shown that the Petunia hybrida ABC transporter PDR1 has a key role in regulating the development of arbuscular mycorrhizae and axillary branches, by functioning as a cellular strigolactone exporter.
Abstract: Strigolactones were originally identified as stimulators of the germination of root-parasitic weeds that pose a serious threat to resource-limited agriculture. They are mostly exuded from roots and function as signalling compounds in the initiation of arbuscular mycorrhizae, which are plant-fungus symbionts with a global effect on carbon and phosphate cycling. Recently, strigolactones were established to be phytohormones that regulate plant shoot architecture by inhibiting the outgrowth of axillary buds. Despite their importance, it is not known how strigolactones are transported. ATP-binding cassette (ABC) transporters, however, are known to have functions in phytohormone translocation. Here we show that the Petunia hybrida ABC transporter PDR1 has a key role in regulating the development of arbuscular mycorrhizae and axillary branches, by functioning as a cellular strigolactone exporter. P. hybrida pdr1 mutants are defective in strigolactone exudation from their roots, resulting in reduced symbiotic interactions. Above ground, pdr1 mutants have an enhanced branching phenotype, which is indicative of impaired strigolactone allocation. Overexpression of Petunia axillaris PDR1 in Arabidopsis thaliana results in increased tolerance to high concentrations of a synthetic strigolactone, consistent with increased export of strigolactones from the roots. PDR1 is the first known component in strigolactone transport, providing new opportunities for investigating and manipulating strigolactone-dependent processes.

472 citations


Proceedings ArticleDOI
16 Apr 2012
TL;DR: A probabilistic framework to make sensible decisions about candidate links and to identify unreliable human workers is developed and developed to improve the quality of the links while limiting the amount of work performed by the crowd.
Abstract: We tackle the problem of entity linking for large collections of online pages; Our system, ZenCrowd, identifies entities from natural language text using state of the art techniques and automatically connects them to the Linked Open Data cloud. We show how one can take advantage of human intelligence to improve the quality of the links by dynamically generating micro-tasks on an online crowdsourcing platform. We develop a probabilistic framework to make sensible decisions about candidate links and to identify unreliable human workers. We evaluate ZenCrowd in a real deployment and show how a combination of both probabilistic reasoning and crowdsourcing techniques can significantly improve the quality of the links, while limiting the amount of work performed by the crowd.

454 citations


Journal ArticleDOI
TL;DR: The aim is to standardise methodologies used in bio-monitoring only and not to limit the use of different methods in pure scientific studies, and to propose two types of recommendations about living (stained) benthic foraminiferal assemblages.

366 citations


Journal ArticleDOI
TL;DR: It is suggested that despite the strong progress that has been made, a consistent unified framework is still missing to link local ecological dynamics to macroevolution, and this is a necessary step in order to interpret observed phylogenetic patterns in a wider ecological context.
Abstract: Ecophylogenetics can be viewed as an emerging fusion of ecology, biogeography andmacroevolution. This new and fastgrowing field is promoting the incorporation of evolution and historical contingencies into the ecological research agenda through the widespread use of phylogenetic data. Including phylogeny into ecological thinking represents an opportunity for biologists from different fields to collaborate and has provided promising avenues of research in both theoretical and empirical ecology, towards a better understanding of the assembly of communities, the functioning of ecosystems and their responses to environmental changes. The time is ripe to assess critically the extent to which the integration of phylogeny into these different fields of ecology has delivered on its promise. Here we review how phylogenetic information has been used to identify better the key components of species interactions with their biotic and abiotic environments, to determine the relationships between diversity and ecosystem functioning and ultimately to establish good management practices to protect overall biodiversity in the face of global change. We evaluate the relevance of information provided by phylogenies to ecologists, highlighting current potential weaknesses and needs for future developments. We suggest that despite the strong progress that has been made, a consistent unified framework is still missing to link local ecological dynamics to macroevolution. This is a necessary step in order to interpret observed phylogenetic patterns in a wider ecological context. Beyond the fundamental question of how evolutionary history contributes to shape communities, ecophylogenetics will help ecology to become a better integrative and predictive science.

356 citations


Journal ArticleDOI
15 Apr 2012-Nature
TL;DR: It is illustrated that PILS proteins are required for auxin-dependent regulation of plant growth by determining the cellular sensitivity to auxin by identifying in silico a novel putative auxin transport facilitator family, called PIN-LIKES.
Abstract: The phytohormone auxin acts as a prominent signal, providing, by its local accumulation or depletion in selected cells, a spatial and temporal reference for changes in the developmental program. The distribution of auxin depends on both auxin metabolism (biosynthesis, conjugation and degradation) and cellular auxin transport. We identified in silico a novel putative auxin transport facilitator family, called PIN-LIKES (PILS). Here we illustrate that PILS proteins are required for auxin-dependent regulation of plant growth by determining the cellular sensitivity to auxin. PILS proteins regulate intracellular auxin accumulation at the endoplasmic reticulum and thus auxin availability for nuclear auxin signalling. PILS activity affects the level of endogenous auxin indole-3-acetic acid (IAA), presumably via intracellular accumulation and metabolism. Our findings reveal that the transport machinery to compartmentalize auxin within the cell is of an unexpected molecular complexity and demonstrate this compartmentalization to be functionally important for a number of developmental processes.

Journal ArticleDOI
TL;DR: It is found that the leucyl-tRNA synthetase (LeuRS) Cdc60 interacts with the Rag GTPase Gtr1 of the EGOC in a leucine-dependent manner and is disrupted by the engagement of CDC60 in editing mischarged tRNA(Leu).

Journal ArticleDOI
01 Mar 2012-Nature
TL;DR: Findings identify circadian transcription of ion channels as a mechanism for cardiac arrhythmogenesis through endogenous circadian rhythmicity under the control of a clock-dependent oscillator, krüppel-like factor 15 (Klf15).
Abstract: Sudden cardiac death exhibits diurnal variation in both acquired and hereditary forms of heart disease, but the molecular basis of this variation is unknown. A common mechanism that underlies susceptibility to ventricular arrhythmias is abnormalities in the duration (for example, short or long QT syndromes and heart failure) or pattern (for example, Brugada's syndrome) of myocardial repolarization. Here we provide molecular evidence that links circadian rhythms to vulnerability in ventricular arrhythmias in mice. Specifically, we show that cardiac ion-channel expression and QT-interval duration (an index of myocardial repolarization) exhibit endogenous circadian rhythmicity under the control of a clock-dependent oscillator, kruppel-like factor 15 (Klf15). Klf15 transcriptionally controls rhythmic expression of Kv channel-interacting protein 2 (KChIP2), a critical subunit required for generating the transient outward potassium current. Deficiency or excess of Klf15 causes loss of rhythmic QT variation, abnormal repolarization and enhanced susceptibility to ventricular arrhythmias. These findings identify circadian transcription of ion channels as a mechanism for cardiac arrhythmogenesis.

Journal ArticleDOI
TL;DR: In this article, a physically based approach for calculating glacier ice thickness distribution and volume is presented and applied to all glaciers and ice caps worldwide, combining glacier outlines of the globally complete Randolph Glacier Inventory with terrain elevation models (Shuttle Radar Topography Mission/Advanced Spaceborne Thermal Emission and Reflection Radiometer).
Abstract: [1] A new physically based approach for calculating glacier ice thickness distribution and volume is presented and applied to all glaciers and ice caps worldwide. Combining glacier outlines of the globally complete Randolph Glacier Inventory with terrain elevation models (Shuttle Radar Topography Mission/Advanced Spaceborne Thermal Emission and Reflection Radiometer), we use a simple dynamic model to obtain spatially distributed thickness of individual glaciers by inverting their surface topography. Results are validated against a comprehensive set of thickness observations for 300 glaciers from most glacierized regions of the world. For all mountain glaciers and ice caps outside of the Antarctic and Greenland ice sheets we find a total ice volume of 170 × 103 ± 21 × 103 km3, or 0.43 ± 0.06 m of potential sea level rise.

Journal ArticleDOI
02 Mar 2012-Science
TL;DR: It is proposed that strain stiffening limits growth, restricts organ bulging, and contributes to the meristem's functional zonation, which means mechanical signals are not just passive readouts of gene action but feed back on morphogenesis.
Abstract: Although genetic control of morphogenesis is well established, elaboration of complex shapes requires changes in the mechanical properties of cells In plants, the first visible sign of leaf formation is a bulge on the flank of the shoot apical meristem Bulging results from local relaxation of cell walls, which causes them to yield to internal hydrostatic pressure By manipulation of tissue tension in combination with quantitative live imaging and finite-element modeling, we found that the slow-growing area at the shoot tip is substantially strain-stiffened compared with surrounding fast-growing tissue We propose that strain stiffening limits growth, restricts organ bulging, and contributes to the meristem's functional zonation Thus, mechanical signals are not just passive readouts of gene action but feed back on morphogenesis

Journal ArticleDOI
28 May 2012-Emotion
TL;DR: Differences in emotion regulation were evident even when controlling for emotion experience and labeling, and implications of these deficits are discussed and future research directions are proposed.
Abstract: It is generally thought that individuals with Asperger's syndrome and high-functioning autism (AS/HFA) have deficits in theory of mind. These deficits have been previously linked to problems with social cognition. However, we reasoned that AS/HFA individuals' Theory of Mind deficits also might lead to problems with emotion regulation. To assess emotional functioning in AS/HFA, 27 AS/HFA adults (16 women) and 27 age-, gender-, and education-matched typically developing (TD) participants completed a battery of measures of emotion experience, labeling, and regulation. With respect to emotion experience, individuals with AS/HFA reported higher levels of negative emotions, but similar levels of positive emotions, compared with TD individuals. With respect to emotion labeling, individuals with AS/HFA had greater difficulties identifying and describing their emotions, with approximately two-thirds exceeding the cutoff for alexithymia. With respect to emotion regulation, individuals with AS/HFA used reappraisal less frequently than TD individuals and reported lower levels of reappraisal self-efficacy. Although AS/HFA individuals used suppression more frequently than TD individuals, no difference in suppression self-efficacy was found. It is important to note that these differences in emotion regulation were evident even when controlling for emotion experience and labeling. Implications of these deficits are discussed, and future research directions are proposed.

Journal ArticleDOI
TL;DR: This risk framework identifies opportunities for improvement in alien species RA by integrating quantitative and scoring RAs into arguably the most rigorous quantitative RA framework currently existing, and mapping each study onto this framework, which combines Transport, Establishment, Abundance, Spread and Impact.
Abstract: Some alien species cause substantial impacts, yet most are innocuous. Given limited resources, forecasting risks from alien species will help prioritise management. Given that risk assessment (RA) approaches vary widely, a synthesis is timely to highlight best practices. We reviewed quantitative and scoring RAs, integrating > 300 publications into arguably the most rigorous quantitative RA framework currently existing, and mapping each study onto our framework, which combines Transport, Establishment, Abundance, Spread and Impact (TEASI). Quantitative models generally measured single risk components (78% of studies), often focusing on Establishment alone (79%). Although dominant in academia, quantitative RAs are underused in policy, and should be made more accessible. Accommodating heterogeneous limited data, combining across risk components, and developing generalised RAs across species, space and time without requiring new models for each species may increase attractiveness for policy applications. Comparatively, scoring approaches covered more risk components (50% examined > 3 components), with Impact being the most common component (87%), and have been widely applied in policy (> 57%), but primarily employed expert opinion. Our framework provides guidance for questions asked, combining scores and other improvements. Our risk framework need not be completely parameterised to be informative, but instead identifies opportunities for improvement in alien species RA.

Journal ArticleDOI
TL;DR: This study compares the distribution and abundance of formerly common and widespread native ladybirds before and after the arrival of Harmonia axyridis, a globally rapidly expanding IAS.
Abstract: Aim Invasive alien species (IAS) are recognized as major drivers of biodiversity loss, but few causal relationships between IAS and species declines have been documented. In this study, we compare the distribution (Belgium and Britain) and abundance (Belgium, Britain and Switzerland) of formerly common and widespread native ladybirds before and after the arrival of Harmonia axyridis, a globally rapidly expanding IAS

Journal ArticleDOI
TL;DR: Auxin is a key coordinative signal required for many aspects of plant development and its levels are controlled by auxin metabolism and intercellular auxin transport, and a member of PIN auxin transporter family, PIN8 is expressed in male gametophyte of Arabidopsis thaliana and has a crucial role in pollen development and functionality.
Abstract: Auxin is a key coordinative signal required for many aspects of plant development and its levels are controlled by auxin metabolism and intercellular auxin transport. Here we find that a member of PIN auxin transporter family, PIN8 is expressed in male gametophyte of Arabidopsis thaliana and has a crucial role in pollen development and functionality. Ectopic expression in sporophytic tissues establishes a role of PIN8 in regulating auxin homoeostasis and metabolism. PIN8 co-localizes with PIN5 to the endoplasmic reticulum (ER) where it acts as an auxin transporter. Genetic analyses reveal an antagonistic action of PIN5 and PIN8 in the regulation of intracellular auxin homoeostasis and gametophyte as well as sporophyte development. Our results reveal a role of the auxin transport in male gametophyte development in which the distinct actions of ER-localized PIN transporters regulate cellular auxin homoeostasis and maintain the auxin levels optimal for pollen development and pollen tube growth.

Journal ArticleDOI
TL;DR: This paper study the motivation and incentive effects of authority experimentally in an authority-delegation game and find that individuals often retain authority even when its delegation is in their material interest, suggesting that authority has non-pecuniary consequences for utility.
Abstract: Authority and power permeate political, social, and economic life, but empirical knowledge about the motivational origins and consequences of authority is limited. We study the motivation and incentive effects of authority experimentally in an authority-delegation game. Individuals often retain authority even when its delegation is in their material interest – suggesting that authority has non-pecuniary consequences for utility. Authority also leads to over-provision of effort by the controlling parties, while a large percentage of subordinates under-provide effort despite pecuniary incentives to the contrary. Authority thus has important motivational consequences that exacerbate the inefficiencies arising from suboptimal delegation choices.

Journal ArticleDOI
TL;DR: It is reported that the balance between the reparative and regenerative processes is achieved through Smad3-dependent TGFβ signaling, and transient scar formation is an essential step to maintain robustness of the damaged ventricular wall prior to cardiomyocyte replacement.
Abstract: Mammals respond to a myocardial infarction by irreversible scar formation. By contrast, zebrafish are able to resolve the scar and to regenerate functional cardiac muscle. It is not known how opposing cellular responses of fibrosis and new myocardium formation are spatially and temporally coordinated during heart regeneration in zebrafish. Here, we report that the balance between the reparative and regenerative processes is achieved through Smad3-dependent TGFβ signaling. The type I receptor alk5b (tgfbr1b) is expressed in both fibrotic and cardiac cells of the injured heart. TGFβ ligands are locally induced following cryoinjury and activate the signaling pathway both in the infarct area and in cardiomyocytes in the vicinity of the trauma zone. Inhibition of the relevant type I receptors with the specific chemical inhibitor SB431542 qualitatively altered the infarct tissue and completely abolished heart regeneration. We show that transient scar formation is an essential step to maintain robustness of the damaged ventricular wall prior to cardiomyocyte replacement. Taking advantage of the reversible action of the inhibitor, we dissected the multifunctional role of TGFβ signaling into three crucial processes: collagen-rich scar deposition, Tenascin C-associated tissue remodeling at the infarct-myocardium interface, and cardiomyocyte proliferation. Thus, TGFβ signaling orchestrates the beneficial interplay between scar-based repair and cardiomyocyte-based regeneration to achieve complete heart regeneration.

Journal ArticleDOI
TL;DR: An overview of the current understanding of the architecture of these pathways is presented, focusing on how the corresponding core signaling protein kinases are wired to ensure an adequate response to nutrient starvation, which enables cells to tide over decades, if not centuries, of famine.
Abstract: Like all microorganisms, yeast cells spend most of their natural lifetime in a reversible, quiescent state that is primarily induced by limitation for essential nutrients. Substantial progress has been made in defining the features of quiescent cells and the nutrient-signaling pathways that shape these features. A view that emerges from the wealth of new data is that yeast cells dynamically configure the quiescent state in response to nutritional challenges by using a set of key nutrient-signaling pathways, which (1) regulate pathway-specific effectors, (2) converge on a few regulatory nodes that bundle multiple inputs to communicate unified, graded responses, and (3) mutually modulate their competences to transmit signals. Here, I present an overview of our current understanding of the architecture of these pathways, focusing on how the corresponding core signaling protein kinases (i.e. PKA, TORC1, Snf1, and Pho85) are wired to ensure an adequate response to nutrient starvation, which enables cells to tide over decades, if not centuries, of famine.

Journal ArticleDOI
TL;DR: A direct role of PI3K/Akt signaling in metastatic cancer development is illustrated and Twist1 phosphorylation could be a potential therapeutic target in clinical cancer treatment.
Abstract: Metastatic breast tumor cells display an epithelial–mesenchymal transition (EMT) that increases cell motility, invasion, and dissemination. Although the transcription factor Twist1 has been shown to contribute to EMT and cancer metastasis, the signaling pathways regulating Twist1 activity are poorly understood. Here, we show that Twist1 is ubiquitously phosphorylated in 90% of 1,532 invasive human breast tumors. Akt/protein kinase B (PKB)–mediated Twist1 phosphorylation promotes EMT and breast cancer metastasis by modulating its transcriptional target TGF-β2, leading to enhanced TGF-β receptor signaling, which in turn maintains hyperactive phosphoinositide 3-kinase (PI3K)/Akt signaling. Preventing phosphorylation of Twist1, as well as depletion of TGF-β2, significantly impaired the metastatic potential of cancer cells in vivo , indicating a key role of phosphorylated Twist1 (phospho-Twist1) in mediating cross-talk between the PI3K/Akt and TGF-β/Smad signaling axes that supports metastatic tumor development. Our results describe a novel signaling event linking PI3K/Akt hyperactivation in tumor cells to direct regulation of Twist1 activation and tumor metastasis. Significance: We identified the first phospho-Twist1 transcriptional target TGF-β2, which mediates cross-talk between PI3K/Akt and TGF-β signaling and promotes tumor metastasis. Our results thus illustrate a direct role of PI3K/Akt signaling in metastatic cancer development and suggest that Twist1 phosphorylation could be a potential therapeutic target in clinical cancer treatment. Cancer Discovery; 2(3); 248–59. ©2012 AACR . This article is highlighted in the In This Issue feature, [p. 193][1] [1]: /lookup/volpage/2/193?iss=3

Journal ArticleDOI
TL;DR: Inclusive education is an appropriate educational option for primary pupils with ID who require extensive support in school who made slightly more progress in literacy skills than children attending special schools.
Abstract: Background While an extensive body of research has examined the outcomes of inclusion for pupils with special needs, in particular learning disabilities, its effects on the development of children with intellectual disabilities (ID) have been less explored. As inclusive practices tend to be more common for this group of children, it is important to acquire more knowledge on this issue. Methods A comparative study with an experimental group of 34 children with ID fully included in general education classrooms with support, and a control group of 34 comparable children in special schools has been conducted. The progress accomplished by these two groups in their academic achievement and adaptive behaviour has been compared over two school years. Results Included children made slightly more progress in literacy skills than children attending special schools. No differences were found between the progress of the two groups in mathematics and adaptive behaviour. Conclusions Inclusive education is an appropriate educational option for primary pupils with ID who require extensive support in school.

Journal ArticleDOI
TL;DR: In this paper, the authors analyzed nine high-alpine catchments spread over the Swiss Alps, selected for their relevance to a wide range of morphological characteristics, and carried out runoff projections until the end of the current century by applying the Glacier Evolution Runoff Model (GERM) and climate scenarios generated in the framework of the ENSEMBLES project.
Abstract: The Alps are often referred to as the ‘water tower of Europe’. In Switzerland, many branches of the economy, especially the hydropower industry, are closely linked to and dependent on the availability of water. Assessing the impact of climate change on streamflow runoff is, thus, of great interest. Major efforts have already been made in this respect, but the analyses often focus on individual catchments and are difficult to intercompare. In this article, we analysed nine high-alpine catchments spread over the Swiss Alps, selected for their relevance to a wide range of morphological characteristics. Runoff projections were carried out until the end of the current century by applying the Glacier Evolution Runoff Model (GERM) and climate scenarios generated in the framework of the ENSEMBLES project. We focused on assessing the uncertainty induced by the unknown climate evolution and provided general, statistically based statements, which should be useful as a ‘rule of thumb’ for analyses addressing questions related to water management. Catchments with a high degree of glacierization will undergo the largest changes. General statements about absolute variations in discharge are unreliable, but an overall pattern, with an initial phase of increased annual discharge, followed by a phase with decreasing discharge, is recognizable for all catchments with a significant degree of glacierization. In these catchments, a transition from glacial and glacio-nival regime types to nival will occur. The timing of maximal annual runoff is projected to occur before 2050 in all basins. The time of year with maximal daily discharges is expected to occur earlier at a rate of 4·4 ± 1·7 days per decade. Compared to its present level, the contribution of snow- and icemelt to annual discharge is projected to drop by 15 to 25% until the year 2100. Copyright © 2011 John Wiley & Sons, Ltd.

Journal ArticleDOI
TL;DR: A pronounced spin-phonon coupling in pnictides that supports rapid development of a macroscopic order on small vibrational displacement even without breaking the symmetry of the crystal is attest to.
Abstract: The interplay among charge, spin and lattice degrees of freedom in solids gives rise to intriguing macroscopic quantum phenomena such as colossal magnetoresistance, multiferroicity and high-temperature superconductivity. Strong coupling or competition between various orders in these systems presents the key to manipulate their functional properties by means of external perturbations such as electric and magnetic fields or pressure. Ultrashort and intense optical pulses have emerged as an interesting tool to investigate elementary dynamics and control material properties by melting an existing order. Here, we employ few-cycle multi-terahertz pulses to resonantly probe the evolution of the spin-density-wave (SDW) gap of the pnictide compound BaFe(2)As(2) following excitation with a femtosecond optical pulse. When starting in the low-temperature ground state, optical excitation results in a melting of the SDW order, followed by ultrafast recovery. In contrast, the SDW gap is induced when we excite the normal state above the transition temperature. Very surprisingly, the transient ordering quasi-adiabatically follows a coherent lattice oscillation at a frequency as high as 5.5 THz. Our results attest to a pronounced spin-phonon coupling in pnictides that supports rapid development of a macroscopic order on small vibrational displacement even without breaking the symmetry of the crystal.

Journal ArticleDOI
TL;DR: The design and performance of a wavelength-dispersive type spectrometer based on the von Hamos geometry equipped with a segmented-type crystal for x-ray diffraction and an energy resolution in the order of 0.25 eV and 1 eV is reported.
Abstract: We report on the design and performance of a wavelength-dispersive type spectrometer based on the von Hamos geometry. The spectrometer is equipped with a segmented-type crystal for x-ray diffraction and provides an energy resolution in the order of 0.25 eV and 1 eV over an energy range of 8000 eV-9600 eV. The use of a segmented crystal results in a simple and straightforward crystal preparation that allows to preserve the spectrometer resolution and spectrometer efficiency. Application of the spectrometer for time-resolved resonant inelastic x-ray scattering and single-shot x-ray emission spectroscopy is demonstrated.

Journal ArticleDOI
TL;DR: Adult ADHD was significantly associated with lower age, low educational level, unemployment, marital status (never married and divorced), and rural residency, and no association was found with gender.
Abstract: Little research on the prevalence and correlates of adult ADHD has been conducted outside the United States. The aim of the present study was to estimate the prevalence and correlates of adult ADHD in a large representative sample of the German population aged 18–64 years (n = 1,655). Two self-rating screening instruments to assess childhood and adult ADHD symptomatology were used to estimate the prevalence of ADHD. A 4-item screening tool was used to assess probable cases of current depression and anxiety (Patient Health Questionnaire). The estimated crude prevalence rate of current ADHD was 4.7%. Adult ADHD was significantly associated with lower age, low educational level, unemployment, marital status (never married and divorced), and rural residency. No association was found with gender. Adult ADHD was strongly associated with positive screening results for depression and anxiety. ADHD is a common disorder of adulthood, is associated with significant social impairment and psychiatric co-morbidity, and should receive further research attention.

Journal ArticleDOI
TL;DR: It is recommended that eradication measures should generally concentrate on the very early phase of invasions when infestations are still relatively small, and some factors suggested as being crucial may be less important than previously thought, at least for the organisms tested here.
Abstract: Eradication aims at eliminating populations of alien organisms from an area. Since not all eradications are successful, several factors have been proposed in the literature (mainly by referring to case studies) to be crucial for eradication success, such as infestation size or reaction time. To our knowledge, however, no study has statistically evaluated which factors affect eradication success and attempted to determine their relative importance. We established a unique global dataset on 136 eradication campaigns against 75 species (invasive alien invertebrates, plants and plant pathogens) and statistically tested whether the following factors, proposed by others were significantly related to eradication success: (1) the reaction time between the arrival/detection of the organism and the start of the eradication campaign; (2) the spatial extent of the infestation; (3) the level of biological knowledge of the organism; and (4) insularity. Of these, only the spatial extent of the infestation was significantly related to the eradication outcome: local campaigns were more successful than regional or national campaigns. Reaction time, the level of knowledge and insularity were all unrelated to eradication success. Hence, some factors suggested as being crucial may be less important than previously thought, at least for the organisms tested here. We found no differences in success rates among taxonomic groups or geographic regions. We recommend that eradication measures should generally concentrate on the very early phase of invasions when infestations are still relatively small.

Journal ArticleDOI
TL;DR: In addition to protein adsorption, the concept of cell "vision" is introduced, which would be recognized as another crucial factor that should be considered for the safe design of any type of nanoparticles that will be used in specific biomedical applications.
Abstract: Engineered nanoparticles are increasingly being considered for use as biosensors, imaging agents and drug delivery vehicles Their versatility in design and applications make them an attractive proposition for new biological and biomedical approaches Despite the remarkable speed of development in nanoscience, relatively little is known about the interaction of nanoscale objects with living systems In a biological fluid, proteins associate with nanoparticles, and the amount and the presentation of the proteins on their surface could lead to a different in vivo response than an uncoated particle Here, in addition to protein adsorption, we are going to introduce concept of cell “vision”, which would be recognized as another crucial factor that should be considered for the safe design of any type of nanoparticles that will be used in specific biomedical applications The impact of exactly the same nanoparticles on various cells is significantly different and could not be assumed for other cells; the possible mechanisms that justify this cellular response relate to the numerous detoxification strategies that any particular cell can utilize in response to nanoparticles The uptake and defence mechanism could be considerably different according to the cell type Thus, what the cell “sees”, when it is faced with nanoparticles, is most likely dependent on the cell type