bluuebunny/crossref_metadata_2025_split huggingface dataset:
OPPORTUNITY AND PREFERENCE LEARNING
Authors: Schubert Christian 
Published: May 2015

Abstract:Robert Sugden has suggested a normative standard of freedom as ‘opportunity’ that is supposed to help realign normative economics – with its traditional rational choice orientation – with behavioural economics. While allowing preferences to be incoherent, he wants to maintain the anti-paternalist stance of orthodox welfare economics. His standard, though, presupposes that people respond to uncertainty about their own future preferences by dismissing any kind of self-constraint. We argue that the approach lacks psychological substance: Sugden's normative benchmark – the ‘responsible person’ – can hardly serve as a convincing role model in a contractarian setting. An alternative concept is introduced, and some implications are briefly discussed.
The transformation of rural elites in late medieval Flanders: oligarchy, state formation and social change in the Liberty of Bruges (c. 1350–c. 1525)
Authors: BUYLAERT FREDERIK , RAMANDT ANDY 
Published: May 2015

AbstractProceeding from an in-depth analysis of the Liberty of Bruges, an important rural district in the late medieval Low Countries, this contribution frames rural elite formation by means of two debates which are seldom used in combination, namely, the debates on state building and on the commercialisation of rural society. We challenge the thesis, inspired by modernisation theory, that socio-economic transformation engendered political change in pre-modern Europe as newly emerging rural bourgeoisies are alleged to have become an important political factor, shifting their allegiances between lords and peasants as they saw fit. The evidence discussed shows instead a trend towards oligarchy from the fifteenth century onwards, in which an increasingly exclusive social network came to combine hitherto separated forms of political power, largely at the expense of the growing number of wealthy rural bourgeois. It is argued that this transformation of the rural political elites is closely tied to changes in the established relations between the central government and the regional elites of the Low Countries.
The role of autocatalysis on the chemical diversity of the prebiotic ocean of early Earth
Authors: Canepa Carlo 
Published: May 2015

AbstractThe spontaneous formation of catalytic polypeptides of various lengths in a primordial ocean endowed with a source of amino acids from micrometeorites was investigated and found to be sufficient to induce the transformation of potential substrates under the assumption of a high propensity of the environment to catalyse the formation of the peptide bond. This work aims to include in this picture the effect of autocatalysis, i.e. the ability of a polypeptide with a specific length to promote the formation of the peptide bond. Once the formation of an autocatalytic species is attained, the concentrations of the polypeptides, substrates and products of reaction exhibit a time-dependent rate of formation and undergo a catastrophic change. While in the absence of autocatalysis the concentrations of polypeptides are stationary and the formation of reaction products is limited by the proper frequency λ, autocatalysis induces a steady growth of the concentrations of polypeptides and a 100 − 105-fold increase of reaction products at t = ω−1<0.46 Gyr, with a subsequent linear growth in time according to the law u/z0 = 1+s(ω−1+t)/z0, provided the autocatalytic species be active with length fewer than 70 amino acid units. A relationship was found between the catalytic ability of the environment (expressed by the ratio η/ηh of the rate coefficient for peptide bond formation to the corresponding rate coefficient for hydrolysis) and the time of the sharp increase of the concentration of both the polypeptides and their products of transformation. Although the formation of autocatalytic polypeptides is able to rapidly induce a sharp increase in the concentration of both polypeptides and their products of transformation, the crucial formation of the first autocatalytic polypeptides relies on the ability of the environment to promote the formation of the peptide bond. The value of the ratio η/ηh, constrained by the available time for chemical evolution to values bordering the catalytic activity of present-day enzymes, suggests that the correlation between the presence of water and the formation of a complex chemistry should be taken with caution.
Dynamic interplay between catalytic and lectin domains of GalNAc-transferases modulates protein O-glycosylation
Authors: Lira-Navarrete Erandi , de las Rivas Matilde , Compañón Ismael , Pallarés María Carmen , Kong Yun , Iglesias-Fernández Javier , Bernardes Gonçalo J. L. , Peregrina Jesús M. , Rovira Carme , Bernadó Pau , Bruscolini Pierpaolo , Clausen Henrik , Lostao Anabel , Corzana Francisco , Hurtado-Guerrero Ramon 
Published: May 2015

AbstractProtein O-glycosylation is controlled by polypeptide GalNAc-transferases (GalNAc-Ts) that uniquely feature both a catalytic and lectin domain. The underlying molecular basis of how the lectin domains of GalNAc-Ts contribute to glycopeptide specificity and catalysis remains unclear. Here we present the first crystal structures of complexes of GalNAc-T2 with glycopeptides that together with enhanced sampling molecular dynamics simulations demonstrate a cooperative mechanism by which the lectin domain enables free acceptor sites binding of glycopeptides into the catalytic domain. Atomic force microscopy and small-angle X-ray scattering experiments further reveal a dynamic conformational landscape of GalNAc-T2 and a prominent role of compact structures that are both required for efficient catalysis. Our model indicates that the activity profile of GalNAc-T2 is dictated by conformational heterogeneity and relies on a flexible linker located between the catalytic and the lectin domains. Our results also shed light on how GalNAc-Ts generate dense decoration of proteins with O-glycans.
High-power multi-megahertz source of waveform-stabilized few-cycle light
Authors: Pronin O. , Seidel M. , Lücking F. , Brons J. , Fedulova E. , Trubetskov M. , Pervak V. , Apolonski A. , Udem Th. , Krausz F. 
Published: May 2015

AbstractWaveform-stabilized laser pulses have revolutionized the exploration of the electronic structure and dynamics of matter by serving as the technological basis for frequency-comb and attosecond spectroscopy. Their primary sources, mode-locked titanium-doped sapphire lasers and erbium/ytterbium-doped fibre lasers, deliver pulses with several nanojoules energy, which is insufficient for many important applications. Here we present the waveform-stabilized light source that is scalable to microjoule energy levels at the full (megahertz) repetition rate of the laser oscillator. A diode-pumped Kerr-lens-mode-locked Yb:YAG thin-disk laser combined with extracavity pulse compression yields waveform-stabilized few-cycle pulses (7.7 fs, 2.2 cycles) with a pulse energy of 0.15 μJ and an average power of 6 W. The demonstrated concept is scalable to pulse energies of several microjoules and near-gigawatt peak powers. The generation of attosecond pulses at the full repetition rate of the oscillator comes into reach. The presented system could serve as a primary source for frequency combs in the mid infrared and vacuum UV with unprecedented high power levels.
Observation of laser-induced electronic structure in oriented polyatomic molecules
Authors: Kraus P. M. , Tolstikhin O. I. , Baykusheva D. , Rupenyan A. , Schneider J. , Bisgaard C. Z. , Morishita T. , Jensen F. , Madsen L. B. , Wörner H. J. 
Published: May 2015

AbstractAll attosecond time-resolved measurements have so far relied on the use of intense near-infrared laser pulses. In particular, attosecond streaking, laser-induced electron diffraction and high-harmonic generation all make use of non-perturbative light–matter interactions. Remarkably, the effect of the strong laser field on the studied sample has often been neglected in previous studies. Here we use high-harmonic spectroscopy to measure laser-induced modifications of the electronic structure of molecules. We study high-harmonic spectra of spatially oriented CH3F and CH3Br as generic examples of polar polyatomic molecules. We accurately measure intensity ratios of even and odd-harmonic orders, and of the emission from aligned and unaligned molecules. We show that these robust observables reveal a substantial modification of the molecular electronic structure by the external laser field. Our insights offer new challenges and opportunities for a range of emerging strong-field attosecond spectroscopies.
Abnormal hippocampal–thalamic white matter tract development and positive symptom course in individuals at ultra-high risk for psychosis
Authors: Bernard Jessica A , Orr Joseph M , Mittal Vijay A 
Published: May 2015

Abstract
Background/Objectives:
Abnormal development of the hippocampus has been reported in adolescents at ultra-high risk (UHR) for psychosis and thalamic abnormalities have been found. However, the white matter connections between the hippocampus and the thalamus have not been studied. The connections between these regions are of key importance to our understanding of the pathophysiology of psychosis.

Methods:
Twenty-six UHR and 21 healthy age-matched controls were tested at a baseline assessment and 12 months later. Symptoms were assessed at both the time points and all the participants underwent diffusion tensor imaging scans. We used tractography to trace the white matter connections in each individual between the thalamus and hippocampus and then extracted fractional anisotropy (FA) to assess white matter structural integrity.

Results:
There was a significant group by time interaction indicating that FA decreased in UHR, and increased in controls over 12 months. Across both groups, baseline FA of the thalamic–hippocampal tract was predictive of positive symptoms at 12-month follow-up. Critically, this pattern remained significant in UHR individual group alone. At baseline, those with higher FA, indicative of abnormal white matter development, show higher positive symptoms 1 year later.

Conclusions:
Here, we provide evidence to indicate that there are differences in white matter development in hippocampal–thalamic connections, both of which are important nodes in networks associated with schizophrenia. Furthermore, abnormal developmental patterns in UHR individuals are associated with positive symptom course.
Repeatability of evolution on epistatic landscapes
Authors: Bauer Benedikt , Gokhale Chaitanya S. 
Published: May 2015

AbstractEvolution is a dynamic process. The two classical forces of evolution are mutation and selection. Assuming small mutation rates, evolution can be predicted based solely on the fitness differences between phenotypes. Predicting an evolutionary process under varying mutation rates as well as varying fitness is still an open question. Experimental procedures, however, do include these complexities along with fluctuating population sizes and stochastic events such as extinctions. We investigate the mutational path probabilities of systems having epistatic effects on both fitness and mutation rates using a theoretical and computational framework. In contrast to previous models, we do not limit ourselves to the typical strong selection, weak mutation (SSWM)-regime or to fixed population sizes. Rather we allow epistatic interactions to also affect mutation rates. This can lead to qualitatively non-trivial dynamics. Pathways, that are negligible in the SSWM-regime, can overcome fitness valleys and become accessible. This finding has the potential to extend the traditional predictions based on the SSWM foundation and bring us closer to what is observed in experimental systems.
Facile and Sustainable Synthesis of Shaped Iron Oxide Nanoparticles: Effect of Iron Precursor Salts on the Shapes of Iron Oxides
Authors: Sayed Farheen N. , Polshettiwar Vivek 
Published: May 2015

AbstractA facile and sustainable protocol for synthesis of six different shaped iron oxides is developed. Notably, all the six shapes of iron oxides can be synthesised using exactly same synthetic protocol, by simply changing the precursor iron salts. Several of the synthesised shapes are not reported before. This novel protocol is relatively easy to implement and could contribute to overcome the challenge of obtaining various shaped iron oxides in economical and sustainable manner.
High-concentration boron doping of graphene nanoplatelets by simple thermal annealing and their supercapacitive properties
Authors: Yeom Da-Young , Jeon Woojin , Tu Nguyen Dien Kha , Yeo So Young , Lee Sang-Soo , Sung Bong June , Chang Hyejung , Lim Jung Ah , Kim Heesuk 
Published: May 2015

AbstractFor the utilization of graphene in various energy storage and conversion applications, it must be synthesized in bulk with reliable and controllable electrical properties. Although nitrogen-doped graphene shows a high doping efficiency, its electrical properties can be easily affected by oxygen and water impurities from the environment. We here report that boron-doped graphene nanoplatelets with desirable electrical properties can be prepared by the simultaneous reduction and boron-doping of graphene oxide (GO) at a high annealing temperature. B-doped graphene nanoplatelets prepared at 1000 °C show a maximum boron concentration of 6.04 ± 1.44 at %, which is the highest value among B-doped graphenes prepared using various methods. With well-mixed GO and g-B2O3as the dopant, highly uniform doping is achieved for potentially gram-scale production. In addition, as a proof-of-concept, highly B-doped graphene nanoplatelets were used as an electrode of an electrochemical double-layer capacitor (EDLC) and showed an excellent specific capacitance value of 448 F/g in an aqueous electrolyte without additional conductive additives. We believe that B-doped graphene nanoplatelets can also be used in other applications such as electrocatalyst and nano-electronics because of their reliable and controllable electrical properties regardless of the outer environment.
A slippery molecular assembly allows water as a self-erasable security marker
Authors: Thirumalai Rajasekaran , Mukhopadhyay Rahul Dev , Praveen Vakayil K. , Ajayaghosh Ayyappanpillai 
Published: May 2015

AbstractProtection of currency and valuable documents from counterfeit continues to be a challenge. While there are many embedded security features available for document safety, they are not immune to forgery. Fluorescence is a sensitive property, which responds to external stimuli such as solvent polarity, temperature or mechanical stress, however practical use in security applications is hampered due to several reasons. Therefore, a simple and specific stimuli responsive security feature that is difficult to duplicate is of great demand. Herein we report the design of a fluorescent molecular assembly on which water behaves as a self-erasable security marker for checking the authenticity of documents at point of care. The underlying principle involves the disciplined self-assembly of a tailor-made fluorescent molecule, which initially form a weak blue fluorescence (λem = 425 nm, Φf = 0.13) and changes to cyan emission (λem = 488 nm,Φf = 0.18) in contact with water due to a reversible molecular slipping motion. This simple chemical tool, based on the principles of molecular self-assembly and fluorescence modulation, allows creation of security labels and optically masked barcodes for multiple documents authentication.
Resveratrol antibacterial activity against Escherichia coli is mediated by Z-ring formation inhibition via suppression of FtsZ expression
Authors: Hwang Dahyun , Lim Young-Hee 
Published: May 2015

AbstractResveratrol exhibits a potent antimicrobial activity. However, the mechanism underlying its antibacterial activity has not been shown. In this study, the antibacterial mechanism of resveratrol was investigated. To investigate induction of the SOS response, a strain containing the lacZ+gene under the control of an SOS-inducible sulA promoter was constructed. DNA damage was measured by pulse-field gel electrophoresis (PFGE). After resveratrol treatment, the cells were observed by confocal microscopy. For the RNA silencing assay, ftsZ-specific antisense peptide nucleic acid (PNA) was used. Reactive oxygen species (ROS) production increased in Escherichia coli after resveratrol treatment; however, cell growth was not recovered by ROS quenching, indicating that, in this experiment, ROS formation and cell death following resveratrol treatment were not directly correlated. Resveratrol treatment increased DNA fragmentation in cells, while SOS response-related gene expression levels increased in a dose-dependent manner. Cell elongation was observed after resveratrol treatment. Elongation was induced by inhibiting FtsZ, an essential cell-division protein in prokaryotes and resulted in significant inhibition of Z-ring the formation in E. coli. The expression of ftsZ mRNA was suppressed by resveratrol. Our results indicate that resveratrol inhibits bacterial cell growth by suppressing FtsZ expression and Z-ring formation.
Macro-to-micro cortical vascular imaging underlies regional differences in ischemic brain
Authors: Dziennis Suzan , Qin Jia , Shi Lei , Wang Ruikang K. 
Published: May 2015

AbstractThe ability to non-invasively monitor and quantify hemodynamic responses down to the capillary level is important for improved diagnosis, treatment and management of neurovascular disorders, including stroke. We developed an integrated multi-functional imaging system, in which synchronized dual wavelength laser speckle contrast imaging (DWLS) was used as a guiding tool for optical microangiography (OMAG) to test whether detailed vascular responses to experimental stroke in male mice can be evaluated with wide range sensitivity from arteries and veins down to the capillary level. DWLS enabled rapid identification of cerebral blood flow (CBF), prediction of infarct area and hemoglobin oxygenation over the whole mouse brain and was used to guide the OMAG system to hone in on depth information regarding blood volume, blood flow velocity and direction, vascular architecture, vessel diameter and capillary density pertaining to defined regions of CBF in response to ischemia. OMAG-DWLS is a novel imaging platform technology to simultaneously evaluate multiple vascular responses to ischemic injury, which can be useful in improving our understanding of vascular responses under pathologic and physiological conditions and ultimately facilitating clinical diagnosis, monitoring and therapeutic interventions of neurovascular diseases.
The role of 5-HT1A receptors in mediating acute negative effects of antidepressants: implications in pediatric depression
Authors: Rahn K A , Cao Y-J , Hendrix C W , Kaplin A I 
Published: May 2015

AbstractAcute antidepressant exposure elevates the frequency of impulsive behavior and suicidal thoughts in children and adolescents with major depressive disorder (MDD). Long-term antidepressant treatment, however, is beneficial for pediatric MDD, so it is necessary to explore novel treatments that prevent the potentially dangerous consequences of acute antidepressant initiation. In the present study, a treatment strategy designed to reverse the acute negative behavioral effects of antidepressants was tested in rodents. Co-administration of the 5-HT1A receptor (5-HT1AR) antagonist WAY-100635 reversed the negative effects of acute fluoxetine, a serotonin reuptake inhibitor, but not reboxetine, a norepinephrine reuptake inhibitor, supporting the involvement of 5-HT1AR in mediating the negative consequences of acute selective serotonin reuptake inhibitor (SSRI) treatment. No 5-HT1AR antagonists are currently approved for use in pediatric populations, so alternative strategies should be explored. One such strategy was suggested based on the hypothesis that the rate of 5-HT1AR activation and the subsequent inhibition of serotonergic neuron activity caused by acute SSRI administration is proportional to the loading rate of an antidepressant. Existing pharmacological data were examined, and significant correlations were observed between the half-life of antidepressants and the rate of suicide-related events (SREs). Specifically, antidepressants with longer half-lives have lower rates of SREs. On the basis of these data, novel dosing strategies were developed for five antidepressants to mimic the pharmacological profile of the antidepressant with the longest half-life, fluoxetine. These dosing strategies could be used to decrease the rate of SREs associated with acute antidepressant treatment in pediatric MDD until an improved pharmacological treatment is developed.
Specific heat and sound velocity at the relevant competing phase of high-temperature superconductors
Authors: Varma Chandra M. , Zhu Lijun 
Published: May 2015

Significance
A variety of experiments have supported the idea that high-temperature superconductivity is caused by the interaction of quantum mechanical zero-point fluctuations of a competing order with electrons. One of the strangest features of this order is that a transition to it appears to occur without a noticeable specific heat anomaly. We show unambiguously that a proposed order, in which currents spontaneously flow in close loops within each unit cell of the compound, is such that an unusual signature of transition to it is found in the sound velocity experiments but that it is unobservable in the specific heat measurements. Stringent conditions are provided by the analysis for other possible orders to be relevant to the fundamental physics of high-temperature superconductivity.
Bestrophin 1 is indispensable for volume regulation in human retinal pigment epithelium cells
Authors: Milenkovic Andrea , Brandl Caroline , Milenkovic Vladimir M. , Jendryke Thomas , Sirianant Lalida , Wanitchakool Potchanart , Zimmermann Stephanie , Reiff Charlotte M. , Horling Franziska , Schrewe Heinrich , Schreiber Rainer , Kunzelmann Karl , Wetzel Christian H. , Weber Bernhard H. F. 
Published: May 2015

Significance
First insight into the molecular identity of volume-regulated anion channel (VRAC) emerged only recently by demonstrating a role for leucine-rich repeats containing 8A (LRRC8A) in channel activity. Our results now expand on VRAC biology, suggesting a model where VRAC subunit composition is cell type- or tissue-specific rather than a single ubiquitous channel formed solely by LRRC8A. Here, we show that bestrophin 1 (BEST1), but not LRCC8A, is crucial in cell volume regulation in retinal pigment epithelium (RPE) cells differentiated from human-induced pluripotent stem cells (hiPSCs). VRAC-mediated currents were strongly reduced in hiPSC-RPE from macular dystrophy patients with pathologic BEST1 mutations. Our model is further supported by in vivo effects of Best1 deficiency in the mouse that manifest as severe subfertility phenotype due to enhanced abnormal sperm morphology related to impaired volume regulation.