bluuebunny/crossref_metadata_2025_split huggingface dataset:
Matrix Factorizations in Algebra, Geometry, and Physics
Authors: Buchweitz Ragnar-Olaf , Hori Kentaro , Krause Henning , Schweigert Christoph 
Published: June 2014

Let

W

be a polynomial or power series in several variables, or, more generally, a nonzero element in some regular commutative ring. A matrix factorization of

W

consists of a pair of square matrices

X

and

Y

of the same size, with entries in the given ring, such that the matrix product

XY

is

W

multiplied by the identity matrix. For example, if

X

is a matrix whose determinant is

W

and

Y

is its adjoint matrix, then

(X, Y)

is a matrix factorization of

W

.

Such matrix factorizations are nowadays ubiquitous in several different fields in physics and mathematics, including String Theory, Commutative Algebra, Algebraic Geometry, both in its classical and its noncommutative version, Singularity Theory, Representation Theory, Topology, there in particular in Knot Theory.
The workshop has brought together leading researchers and young colleagues from the various input fields; it was the first workshop on this topic in Oberwolfach. For some leading researchers from neighboring fields, this was their first visit to Oberwolfach.
Efficient Generation of Integration-Free Human Induced Pluripotent Stem Cells From Keratinocytes by Simple Transfection of Episomal Vectors
Authors: Piao Yulan , Hung Sandy Shen-Chi , Lim Shiang Y. , Wong Raymond Ching-Bong , Ko Minoru S.H. 
Published: June 2014

Abstract

Keratinocytes represent an easily accessible cell source for derivation of human induced pluripotent stem (hiPS) cells, reportedly achieving higher reprogramming efficiency than fibroblasts. However, most studies utilized a retroviral or lentiviral method for reprogramming of keratinocytes, which introduces undesirable transgene integrations into the host genome. Moreover, current protocols of generating integration-free hiPS cells from keratinocytes are mostly inefficient. In this paper, we describe a more efficient, simple-to-use, and cost-effective method for generating integration-free hiPS cells from keratinocytes. Our improved method using lipid-mediated transfection achieved a reprogramming efficiency of ∼0.14% on average. Keratinocyte-derived hiPS cells showed no integration of episomal vectors, expressed stem cell-specific markers and possessed potentials to differentiate into all three germ layers by in vitro embryoid body formation as well as in vivo teratoma formation. To our knowledge, this represents the most efficient method to generate integration-free hiPS cells from keratinocytes.
Mesenchymal Stromal Cell Therapy Is Associated With Increased Adenovirus-Associated but Not Cytomegalovirus-Associated Mortality in Children With Severe Acute Graft-Versus-Host Disease
Authors: Calkoen Friso G.J. , Vervat Carly , van Halteren Astrid G.S. , Welters Marij J.P. , Veltrop-Duits Louise A. , Lankester Arjan C. , Egeler R. Maarten , Ball Lynne M. , van Tol Maarten J.D. 
Published: June 2014

Abstract
Beneficial effects of mesenchymal stromal cells (MSCs) in patients with severe steroid-refractory acute graft-versus-host disease (aGvHD) have been reported. However, controversy exists about the effect of MSCs on virus-specific T cells. We evaluated 56 patients with grade II-IV aGvHD who responded to steroids (n = 21) or were steroid refractory receiving either MSCs (n = 22) or other second-line therapy (n = 13). Although the overall incidence of cytomegalovirus (CMV), Epstein-Barr virus, and human adenovirus (HAdV) infections was not significantly increased, HAdV infection was associated with decreased survival in children treated with MSCs. Thus, we investigated in vitro the effects of MSCs on virus-specific T cells. Both CMV-specific and, to a lesser extent, HAdV-specific T-cell activation and proliferation were negatively affected by MSCs either after induction of a response in peripheral blood mononuclear cells (PBMCs) or after restimulation of virus-specific T-cell lines. In patient-derived PBMCs, CMV-specific proliferative responses were greatly decreased on first-line treatment of aGvHD with systemic steroids and slowly recovered after MSC administration and tapering of steroids. HAdV-specific T-cell proliferation could not be detected. In contrast, the proportion of CMV- and HAdV-specific effector T cells, measured as interferon-γ-secreting cells, remained stable or increased after treatment with MSCs. In conclusion, although in vitro experimental conditions indicated a negative impact of MSCs on CMV- and HAdV-specific T-cell responses, no solid evidence was obtained to support such an effect of MSCs on T-cell responses in vivo. Still, the susceptibility of steroid-refractory severe aGvHD patients to viral reactivation warrants critical viral monitoring during randomized controlled trials on second-line treatment including MSCs.
Proneural Transcription Factor Atoh1 Drives Highly Efficient Differentiation of Human Pluripotent Stem Cells Into Dopaminergic Neurons
Authors: Sagal Jonathan , Zhan Xiping , Xu Jinchong , Tilghman Jessica , Karuppagounder Senthilkumar S. , Chen Li , Dawson Valina L. , Dawson Ted M. , Laterra John , Ying Mingyao 
Published: June 2014

Abstract
Human pluripotent stem cells (PSCs) are a promising cell resource for various applications in regenerative medicine. Highly efficient approaches that differentiate human PSCs into functional lineage-specific neurons are critical for modeling neurological disorders and testing potential therapies. Proneural transcription factors are crucial drivers of neuron development and hold promise for driving highly efficient neuronal conversion in PSCs. Here, we study the functions of proneural transcription factor Atoh1 in the neuronal differentiation of PSCs. We show that Atoh1 is induced during the neuronal conversion of PSCs and that ectopic Atoh1 expression is sufficient to drive PSCs into neurons with high efficiency. Atoh1 induction, in combination with cell extrinsic factors, differentiates PSCs into functional dopaminergic (DA) neurons with &gt;80% purity. Atoh1-induced DA neurons recapitulate key biochemical and electrophysiological features of midbrain DA neurons, the degeneration of which is responsible for clinical symptoms in Parkinson's disease (PD). Atoh1-induced DA neurons provide a reliable disease model for studying PD pathogenesis, such as neurotoxin-induced neurodegeneration in PD. Overall, our results determine the role of Atoh1 in regulating neuronal differentiation and neuron subtype specification of human PSCs. Our Atoh1-mediated differentiation approach will enable large-scale applications of PD patient-derived midbrain DA neurons in mechanistic studies and drug screening for both familial and sporadic PD.
The filamentary structure of mixing fronts and its control on reaction kinetics in porous media flows
Authors: de Anna Pietro , Dentz Marco , Tartakovsky Alexandre , Le Borgne Tanguy 
Published: June 2014

AbstractThe mixing dynamics resulting from the combined action of diffusion, dispersion, and advective stretching of a reaction front in heterogeneous flows leads to reaction kinetics that can differ by orders of magnitude from those measured in well‐mixed batch reactors. The reactive fluid invading a porous medium develops a filamentary or lamellar front structure. Fluid deformation leads to an increase of the front length by stretching and consequently a decrease of its width by compression. This advective front deformation, which sharpens concentration gradients across the interface, is in competition with diffusion, which tends to increase the interface width and thus smooth concentration gradients. The lamella scale dynamics eventually develop into a collective behavior through diffusive coalescence, which leads to a disperse interface whose width is controlled by advective dispersion. We derive a new approach that quantifies the impact of these filament scale processes on the global mixing and reaction kinetics. The proposed reactive filament model, based on the elementary processes of stretching, coalescence, and fluid particle dispersion, provides a new framework for predicting reaction front kinetics in heterogeneous flows.
Limitations of the potential predictability of meridional mass and heat transports in the North Atlantic
Authors: Tiedje Bente , Baehr Johanna 
Published: June 2014

AbstractThe climatological relevance of the Atlantic meridional overturning circulation (AMOC) stems from its capability to transport heat meridionally. The variability of AMOC and the meridional heat transport (MHT) are intimately linked, but not interchangeable. Here we ask to what extend AMOC's predictability may be used as a proxy for MHT's predictability. We find that the geostrophic parts of MHT and AMOC show similar potential predictability (0∘–45∘N), which originates from the potential predictability of the density field at the western boundary (above 1700 m). Maximum timescales of potential predictability are found for both MHT's and AMOC's geostrophic parts between the subpolar and the subtropical gyre, while meridionally propagating density anomalies at the western boundary limit the potential predictability north and south of the gyre boundary. The inference of MHT predictability from AMOC predictability is thus limited to the geostrophic parts of MHT and AMOC, and particularly adequate at the gyre boundary.
Saturn chorus latitudinal variations
Authors: Menietti J. D. , Hospodarsky G. B. , Shprits Y. Y. , Gurnett D. A. 
Published: June 2014

AbstractThe variation of propagation properties of whistler mode chorus as a function of latitude is not well known at Saturn but is important for the calculation of pitch angle diffusion and nonlinear growth of chorus. The Cassini spacecraft has spent a portion of its orbital time in high‐inclination orbits, allowing traversal of the magnetic equator at nearly constant L shell for several passes. This is important since chorus is believed to propagate dominantly close to the magnetic field direction. We have investigated the change of wave normal angle, whistler mode magnetic intensity, and ambient magnetic field inhomogeneity as a function of latitude observed by the Radio and Plasma Wave investigation onboard the Cassini instrument. We find that wave normal angles along a nearly constant L shell remain close to field‐aligned, except nearest the equator, and whistler mode wave intensity increases from the magnetic equator, according to a power law. The ambient magnetic field shows an inhomogeneity that is lower than Earth's, but there is a lack of drifting‐frequency signatures nearest the equator. The bandwidth of the chorus emission can be described by a simple exponential. The bandwidth increases from the equator, peaking a few degrees away in a region of strong nonlinear growth and then decreases at higher latitudes.
Spatial Bayesian inversion with localized likelihoods: An exact sampling alternative to MCMC
Authors: Walker Matthew , Curtis Andrew 
Published: June 2014

AbstractGeoscientists often use spatially discretized cellular models of the Earth where data in each grid cell provide independent information about the model parameters of interest at that location. In Bayesian inference this information is given as a set of likelihoods describing the (unnormalized) probability of the parameters, given only the data in each cell. Preexisting information about the model parameters' values and their spatial correlations may be described by a prior probability distribution. The prior, likelihoods, and Bayes' rule together specify a posterior probability distribution that describes the resultant state of information over all model parameters. However, due to the high dimensionality of typical models, the posterior is usually only known up to a multiplicative constant and only at specific, numerically evaluated points in the model space (i.e., it is not known analytically). Markov chain Monte Carlo (MCMC) methods are typically used to produce an ensemble of correlated samples from the posterior. These ensembles are slow to converge in distribution to the posterior; indeed, they may not converge in finite time, and detecting their state of convergence is often impossible in practice. Thus, estimates of the posterior obtained in this way may be biased. We derive a recursive algorithm which samples the posterior exactly, so as to avoid these convergence issues. Its computational cost scales with the size of the parameters' sample space, the prior's spatial range of dependency, and the shortest edge dimension of the grid. We develop an approximation to the algorithm such that it may be used on large 2‐D (and potentially 3‐D) model grids. We apply it to synthetic seismic attribute data and obtain results which compare favorably to the results of MCMC (Gibbs) sampling—which exhibits convergence problems.
Triarylphosphine Ligands with Hemilabile Alkoxy Groups: Ligands for Nickel(II)‐Catalyzed Olefin Dimerization Reactions. Hydrovinylation of Vinylarenes, 1,3‐Dienes, and Cycloisomerization of 1,6‐Dienes
Authors: Biswas Souvagya , Zhang Aibin , Raya Balaram , RajanBabu T. V. 
Published: June 2014

AbstractSubstitution of one of the phenyl groups of triphenylphosphine with a 2‐benzyloxy‐, 2‐benzyloxymethyl‐ or 2‐benzyloxyethyl‐phenyl moiety results in a set of simple ligands, which exhibit strikingly different behaviour in various nickel(II)‐catalyzed olefin dimerization reactions. Complexes of ligands with 2‐benzyloxyphenyl‐ and 2‐benzyloxymethylphenyldiphenylphosphine (L5 and L6, respectively) are most active for hydrovinylation (HV) of vinylarenes, with the former leading to extensive isomerization of the primary 3‐aryl‐1‐butenes into the conjugated 2‐aryl‐2‐butenes even at −55 °C. However, 2‐benzyloxymethyl‐substituted ligand L6 is slightly less active, affording up to quantitative yields of the primary products of HV at ambient temperature with no trace of isomerization, thus providing the best option for a practical synthesis of these compounds. In sharp contrast, hydrovinylation of a variety of 1,3‐dienes is best catalyzed by nickel(II) complexes of 2‐benzyloxyphenyldiphenylphosphine, L5. The other two ligands, 2‐benzyloxymethyl‐ (L6) and 2‐benzyloxyethyldiphenylphosphine (L7) are much less effective in the HV of 1,3‐dienes. Nickel(II)‐catalyzed cycloisomerization of 1,6‐dienes into methylenecyclopentanes, a reaction mechanistically related to the other hydrovinylation reactions, is also uniquely effected by nickel(II) complexes of L5, but not of L6 or L7. In an attempt to prepare authentic samples of the methylencyclohexane products, nickel(II) complexes of N‐heterocyclic carbene ligands were examined. In sharp contrast to the phosphines, which give the methylenecyclopentanes, methylenecyclohexanes are the major products in the (N‐heterocyclic carbene)nickel(II)‐mediated reactions.magnified image
Preparation, Characterization, Thermal, and Dielectric Properties of Polypyrrole/h‐BN Nanocomposites
Authors: Madakbaş Seyfullah , Şen Ferhat , Vezir Kahraman Memet , Dumludağ Fatih 
Published: June 2014

ABSTRACTThe aim of this study was to improve thermal stability and dielectric properties of polypyrrole (PPy) by adding hexagonal boron nitride (h‐BN). PPy was synthesized, and PPy/h‐BN nanocomposites were prepared by adding various proportions of h‐BN to PPy. The chemical structures of the samples were investigated by Fourier transform infrared spectroscopy. Thermal properties of the nanocomposites were determined by thermogravimetric analysis and differential scanning calorimetry. X‐ray diffraction analysis of the samples was carried out. The surface morphologies of the samples were investigated by a scanning electron microscopy‐energy dispersive spectroscopy (SEM‐EDS). The obtained results prove that the nanocomposite system is more thermally stable than the pure PPy. Dielectric measurements revealed that the dielectric constant of the pellets increased with increasing temperature and decreased with increasing frequency. It is also observed that the dielectric constant of the pellets decreased with increasing nano‐hBN content (between 1 and 4 wt%).
Preterm delivery as a predictor of diurnal cortisol profiles in adulthood: Evidence from Cebu, Philippines
Authors: Lee James , Fried Ruby , Thayer Zaneta , Kuzawa Christopher W. 
Published: June 2014

ObjectivesFetal exposure to elevated maternal cortisol can permanently modify hypothalamic–pituitary–adrenal (HPA) axis function, and thereby have long‐term health impacts. Maternal cortisol steadily increases throughout normal pregnancy, but is abnormally high in preterm deliveries (<37 weeks). Prematurity remains a widespread public health problem, yet little is known about its potential long‐term effects on adult HPA function. Here we test the hypothesis that diurnal cortisol profiles measured in young adulthood will vary based upon an individual's preterm status.MethodsDiurnal salivary cortisol profiles, a marker of HPA‐axis function, were measured in 1,403 young adults (ages 21–23 years) participating in the Cebu Longitudinal Health and Nutrition Survey, located in Metropolitan Cebu City, Philippines.ResultsMales who had been born preterm exhibited lower morning cortisol and non‐significantly elevated evening cortisol, resulting in a more adverse, flatter rate of decline across the day. In contrast, there were no significant differences by preterm status in cortisol measured at any time of day in females.ConclusionsThese findings point to potential long‐term effects of having been born preterm on adult HPA‐axis function, and add to evidence from this and other populations for sex differences in the biological and health impacts of prenatal stress exposure. Am. J. Hum. Biol. 26:598–602, 2014. © 2014 Wiley Periodicals, Inc.
The upper respiratory pyramid: Early factors and later treatment utilization in World Trade Center exposed firefighters
Authors: Niles Justin K. , Webber Mayris P. , Liu Xiaoxue , Zeig‐Owens Rachel , Hall Charles B. , Cohen Hillel W. , Glaser Michelle S. , Weakley Jessica , Schwartz Theresa M. , Weiden Michael D. , Nolan Anna , Aldrich Thomas K. , Glass Lara , Kelly Kerry J. , Prezant David J. 
Published: June 2014

BackgroundWe investigated early post 9/11 factors that could predict rhinosinusitis healthcare utilization costs up to 11 years later in 8,079 World Trade Center‐exposed rescue/recovery workers.MethodsWe used bivariate and multivariate analytic techniques to investigate utilization outcomes; we also used a pyramid framework to describe rhinosinusitis healthcare groups at early (by 9/11/2005) and late (by 9/11/2012) time points.ResultsMultivariate models showed that pre‐9/11/2005 chronic rhinosinusitis diagnoses and nasal symptoms predicted final year healthcare utilization outcomes more than a decade after WTC exposure. The relative proportion of workers on each pyramid level changed significantly during the study period.ConclusionsDiagnoses of chronic rhinosinusitis within 4 years of a major inhalation event only partially explain future healthcare utilization. Exposure intensity, early symptoms and other factors must also be considered when anticipating future healthcare needs. Am. J. Ind. Med. 57:857–865, 2014. © 2014 Wiley Periodicals, Inc.
Elastic and Wearable Wire‐Shaped Lithium‐Ion Battery with High Electrochemical Performance
Authors: Ren Jing , Zhang Ye , Bai Wenyu , Chen Xuli , Zhang Zhitao , Fang Xin , Weng Wei , Wang Yonggang , Peng Huisheng 
Published: June 2014

AbstractA stretchable wire‐shaped lithium‐ion battery is produced from two aligned multi‐walled carbon nanotube/lithium oxide composite yarns as the anode and cathode without extra current collectors and binders. The two composite yarns can be well paired to obtain a safe battery with superior electrochemical properties, such as energy densities of 27 Wh kg−1 or 17.7 mWh cm−3 and power densities of 880 W kg−1 or 0.56 W cm−3, which are an order of magnitude higher than the densities reported for lithium thin‐film batteries. These wire‐shaped batteries are flexible and light, and 97 % of their capacity was maintained after 1000 bending cycles. They are also very elastic as they are based on a modified spring structure, and 84 % of the capacity was maintained after stretching for 200 cycles at a strain of 100 %. Furthermore, these novel wire‐shaped batteries have been woven into lightweight, flexible, and stretchable battery textiles, which reveals possible large‐scale applications.
Thermophorese in Nanoliter‐Tropfen zur Quantifizierung von Aptamer‐Bindungen
Authors: Seidel Susanne A. I. , Markwardt Niklas A. , Lanzmich Simon A. , Braun Dieter 
Published: June 2014

AbstractBiomolekulare Interaktionen, die von zentraler Bedeutung für Pharmakologie und Diagnostik sind, können durch Thermophorese quantifiziert werden. Diese reagiert empfindlich auf bindungsinduzierte Größen‐, Ladungs‐ oder Konformationsänderungen. Etablierte Kapillarmessungen verbrauchen mindestens 0.5 μL pro Probe. Wir reduzierten den Probenverbrauch um den Faktor 50, indem wir 10‐nL‐Tropfen verwendeten, die mit akustischer Flüssigkeitsübertragung (Labcyte) hergestellt wurden. Die Tropfen wurden in einem Öl‐Tensid‐Gemisch stabilisiert und mit einem Infrarotlaser lokal erwärmt. Temperaturerhöhung, Marangoni‐Fluss und Konzentrationsverteilung wurden mit Fluoreszenzmikroskopie und numerischer Simulation analysiert. In 10‐nL‐Tropfen quantifizierten wir Affinität, Kooperativität und Pufferabhängigkeit des AMP‐Aptamers. Die Miniaturisierung und das 1536‐Well‐Platten‐Format machen die Methode hochdurchsatzfähig und automatisierbar. Dies forciert innovative Anwendungen in der serologischen Diagnostik und markierungsfreien Wirkstoffsuche.
Versatile Preparation of Nonspherical Multiple Hydrogel Core PAM/PEG Emulsions and Hierarchical Hydrogel Microarchitectures
Authors: Guo Song , Yao Tong , Ji Xiaobo , Zeng Changfeng , Wang Chongqing , Zhang Lixiong 
Published: June 2014

AbstractThe preparation of nonspherical materials composed of separated multicomponents by droplet‐based microfluidics remains a challenge. Based on polymerization‐induced phase separation and droplet coalescence in microfluidics, we prepared emulsions of variously shaped PAM/PEG core/shell droplets and hydrogels composed of two separated components, which show flexible and transformable hierarchical structures and microarchitectures. We find that AM/PEG aqueous droplets form a core/shell structure after polymerization resulting from phase separation. Thus multicore/shell droplets are easily produced by coalescence of core/shell structures. By changing the polymerization temperature and the flow rate, the morphology of the multicore droplets and the hydrogel can be easily adjusted. The hydrogels exhibit apparent anisotropy and different protein release rates depending on their structures. The preparation technique is simple and versatile and the resulting hydrogels have potential applications in many fields.
Funktionalisierung eines cyclo‐P5‐Liganden durch Hauptgruppenelement‐Nukleophile
Authors: Mädl Eric , Butovskii Mikhail V. , Balázs Gábor , Peresypkina Eugenia V. , Virovets Alexander V. , Seidl Michael , Scheer Manfred 
Published: June 2014

AbstractDurch die Reaktion von [Cp*Fe(η5‐P5)] (1; Cp* = η5‐C5Me5) mit verschiedenen Nucleophilen werden beispiellose funktionalisierte Produkte mit einem η4‐P5‐Ring erhalten. Mit LiCH2SiMe3 und LiNMe2 werden die Monoanionen [Cp*Fe(η4‐P5CH2SiMe3)]− bzw. [Cp*Fe(η4‐P5NMe2)]− gebildet. Die Reaktion von 1 mit NaNH2 führt zur Bildung des Trianions [{Cp*Fe(η4‐P5)}2N]3−, während die Reaktion mit LiPH2 [Cp*Fe(η4‐P5PH2)]− als das Hauptprodukt ergibt, mit {[Cp*Fe(η4‐P5)]2PH}2− als Nebenprodukt. Die berechneten Energieprofile der Reaktionen liefern eine Erklärung für die Bildung der unterschiedlichen Produkte.