bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reconciling precipitation trends in Alaska: 2. Gridded data analyses
Authors: McAfee Stephanie , Guentchev Galina , Eischeid Jon 
Published: November 2014

AbstractThere is a great deal of interest in whether and how Alaska's precipitation is changing but little agreement in the existing peer‐reviewed literature. To provide insight on this question, we have selected three commonly used 0.5° resolution gridded precipitation products that have long‐term monthly data coverage (Climatic Research Unit TS3.10.1, Global Precipitation Climatology Centre Full Data Reanalysis version 5, and University of Delaware version 2.01) and evaluated their homogeneity and trends with multiple methods over two periods, 1950–2008 and 1980–2008. All three data sets displayed common broadscale features of Alaska's precipitation climatology, but there were substantial differences between them in terms of average precipitation amount and interannual variability. Temporal inhomogeneity was a significant concern over Alaska in gridded precipitation products, as it was in the state's coastal weather stations. Although underlying station inhomogeneities were inherited to some extent by all of the gridded data sets, differences in data set construction contributed to dissimilarities in inhomogeneity, as well. There were contrasts in trends between the two time periods, and some minor discrepancies occurred as a function of the trend detection method, but the main disparities stemmed from choice of data set. Indeed, there were large areas where these data sets disagreed on both the sign and significance of precipitation trends. Until further analysis can resolve these differences, researchers using gridded precipitation data or evaluating studies based on such data should interpret results with extreme caution.
A simple modeling approach to elucidate the main transport processes and predict invasive spread: River‐mediated invasion of Ageratina adenophora in China
Authors: Horvitz Nir , Wang Rui , Zhu Min , Wan Fang‐Hao , Nathan Ran 
Published: November 2014

AbstractA constantly increasing number of alien species invade novel environments and cause enormous damage to both biodiversity and economics worldwide. This global problem is calling for better understanding of the different mechanisms driving invasive spread, hence quantification of a range of dispersal vectors. Yet, methods for elucidating the mechanisms underlying large‐scale invasive spread from empirical patterns have not yet been developed. Here we propose a new computationally efficient method to quantify the contribution of different dispersal vectors to the spread rate of invasive plants. Using data collected over 30 years regarding the invasive species Ageratina adenophora since its detection at the Sichuan province, we explored its spread by wind and animals, rivers, and roads into 153 subcounties in the Sichuan, Chongqingshi, and Hubei provinces of China. We found that rivers are the most plausible vector for the rapid invasion of this species in the study area. Model explorations revealed robustness to changes in key assumptions and configuration. Future predictions of this ongoing invasion process project that the species will quickly spread along the Yangtze River and colonize large areas within a few years. Further model developments would provide a much needed tool to mechanistically and realistically describe large‐scale invasive spread, providing insights into the underlying mechanisms and an ability to predict future spatial invasive dynamics.
Comonotonicity
Authors: Dhaene Jan , Vanduffel Steven , Goovaerts Marc J. 
Published: November 2014

AbstractIn an actuarial or financial context it is often necessary to calculate the distribution function or risk measures for random variables of the type where the marginal distributions of theXiare known but their dependence structure is too difficult to work with. Comonotonicity, which is an extremal form of positive dependence, can be useful to determine easily computable and accurate upper and lower bounds for the distribution ofS, and hence also for risk measures related toS.
Equity‐Linked Life Insurance
Authors: Bacinello Anna R. 
Published: November 2014

Abstract

Equity‐linked life insurance contracts are characterized by the fact that benefits are directly linked to the value of an investment portfolio, typically composed of units of one or more mutual funds and kept separate from the other assets of the insurance company. These contracts generally imply a rather high level of financial risk that can be totally charged to the policyholder, in
pure equity‐linked contracts
, or shared between the policyholder and the insurance company, in
guaranteed equity‐linked contracts
. In the first case the insurance company acts as a mere financial intermediary, while in the second case it has to set up suitable hedging strategies because the financial risk is of systematic nature and cannot be eliminated by sufficiently increasing the size of its portfolio. In this contribution we first describe, in general terms, the main characteristics of equity‐linked products and their advantages with respect to other types of life insurance and investment contracts. Then we pass to analyze how the investment portfolio to which benefits are linked evolves over time and, finally, to present some possible approaches that the insurance company can follow in order to hedge the liabilities arising from the issue of minimum guarantees.
Insurance Applications of Life Tables
Authors: Pitacco Ermanno 
Published: November 2014

Abstract
Mortality constitutes one of the main causes of risk in a life insurance portfolio (or pension plan). Many risk factors contribute to determine the mortality in a portfolio. In particular, at an individual level, the insured's age has an important role. In this article, we first describe the features of a (period) life table which constitutes the basic tool to represent the age pattern of mortality, and the applications of life tables to the calculation of expected present values (or “actuarial values”) in life insurance. Next, we introduce the ideas underlying the projected life tables, meant as a tool to represent future mortality. Finally, we focus on randomness in the results of a life insurance portfolio (cash flows, profits, etc.), and the use of stochastic models.
Reinsurance
Authors: Simões Onofre , Lourdes Centeno Maria 
Published: November 2014

Abstract
We start by giving an overview of the importance of reinsurance for the management of direct insurers and introduce most of the reinsurance concepts, namely, by presenting the different forms that reinsurance contracts can assume and how they affect the retained business of the insurers. We also explain how reinsurance can be placed and finish with some considerations about designing reinsurance programmes.
Securitization/Life
Authors: Blake David , Dowd Kevin 
Published: November 2014

AbstractThis article examines the securitization of life‐related risks. It briefly reviews the history of such securitizations and sets out their potential benefits to the firms and investors involved. It then explains their mechanics and examines four recent important classes: “block of business” securitizations, regulatory reserving or XXX securitizations, the issuance of mortality or longevity bonds, and pension bulk buyout securitizations.
A Bis‐Sulfonyl O,C,O Aryl Pincer Ligand and its Tin(II) Complex: Synthesis, Structural Studies, and DFT Calculations
Authors: El Ezzi Mohammad , Lenk Romaric , Madec David , Sotiropoulos Jean‐Marc , Mallet‐Ladeira Sonia , Castel Annie 
Published: November 2014

AbstractThe efficiency of the deprotonated aryl bis‐sulfone [2,6‐{(p‐tolyl)SO2}2C6H3]− as an O,C,O‐coordinating pincer‐type ligand was described. The bis‐sulfone precursor was synthesized using a straightforward palladium‐catalyzed cross‐coupling reaction. As a result of directed ortho metalation (DoM) through sulfonyl groups, a selective lithiation of the aryl group was achieved and the corresponding carbanion was isolated and its structure determined by single‐crystal X‐ray diffraction analysis. A heteroleptic tin(II) complex has been prepared by a nucleophilic substitution reaction. Crystallographic analysis and DFT calculations indicate that the bis‐sulfonyl moiety acts as a new O,C,O‐coordinating pincer‐type ligand with intramolecular SO coordination to a tin(II) center. The cis form with the two nonbonded oxygen atoms of the sulfonyl groups on the same side is preferentially obtained.
Enantioselective Oxidative Gold Catalysis Enabled by a Designed Chiral P,N‐Bidentate Ligand
Authors: Ji Kegong , Zheng Zhitong , Wang Zhixun , Zhang Liming 
Published: November 2014

AbstractA newly developed P,N‐bidentate ligand enables enantioselective intramolecular cyclopropanation by a reactive α‐oxo gold carbene intermediate generated in situ. The ligand design is based on our previously proposed structure (with a well‐organized triscoordinated gold center) of the carbene intermediate in the presence of a P,N‐bidentate ligand. A C2‐symmetric piperidine ring was incorporated in the ligand as the nitrogen‐containing moiety. A range of racemic transformations of α‐oxo gold carbene intermediates have been developed recently, and this new class of chiral ligands could enable their modification for asymmetric synthesis, as demonstrated in this study.
Schaltung bakterieller Adhäsion auf glycosylierten Oberflächen durch reversible Reorientierung der Kohlenhydratliganden
Authors: Weber Theresa , Chandrasekaran Vijayanand , Stamer Insa , Thygesen Mikkel B. , Terfort Andreas , Lindhorst Thisbe K. 
Published: November 2014

AbstractIn vielen biologischen Systemen wird die Erkennung von Oberflächen durch die Wechselwirkung von Kohlenhydrat‐spezifischen Proteinen (Lektinen) mit den Kohlenhydratepitopen (Liganden) der ungeordneten Glycokonjugatschicht (Glycokalyx) der Zellen gesteuert. Damit es zu einer erfolgreichen Anbindung kommt, müssen sich diese Liganden geeignet im Raum orientieren. Wir stellen zum ersten Mal ein Modellsystem vor, in dem die Orientierung der Liganden auf einer Oberfläche kontrolliert variiert wird, ohne dabei ihre strukturelle Qualität in irgendeiner Weise zu verändern. Der Schlüssel für die Kontrolle der Ligandorientierung liegt in der Konjugation an photoschaltbare Azobenzoleinheiten.
Functional Dynamics of Deuterated β2‐Adrenergic Receptor in Lipid Bilayers Revealed by NMR Spectroscopy
Authors: Kofuku Yutaka , Ueda Takumi , Okude Junya , Shiraishi Yutaro , Kondo Keita , Mizumura Takuya , Suzuki Shiho , Shimada Ichio 
Published: November 2014

AbstractG‐protein‐coupled receptors (GPCRs) exist in conformational equilibrium between active and inactive states, and the former population determines the efficacy of signaling. However, the conformational equilibrium of GPCRs in lipid bilayers is unknown owing to the low sensitivities of their NMR signals. To increase the signal intensities, a deuteration method was developed for GPCRs expressed in an insect cell/baculovirus expression system. The NMR sensitivities of the methionine methyl resonances from the β2‐adrenergic receptor (β2AR) in lipid bilayers of reconstituted high‐density lipoprotein (rHDL) increased by approximately 5‐fold upon deuteration. NMR analyses revealed that the exchange rates for the conformational equilibrium of β2AR in rHDLs were remarkably different from those measured in detergents. The timescales of GPCR signaling, calculated from the exchange rates, are faster than those of receptor tyrosine kinases and thus enable rapid neurotransmission and sensory perception.
Indicator Displacement Assays Inside Live Cells
Authors: Norouzy Amir , Azizi Zahra , Nau Werner M. 
Published: November 2014

AbstractThe macrocycle p‐sulfonatocalix[4]arene (CX4) and the fluorescent dye lucigenin (LCG) form a stable host–guest complex, in which the dye fluorescence is quenched. Incubation of live V79 and CHO cells with the CX4/LCG chemosensing ensemble resulted in its spontaneous uptake. Subsequent addition of choline, acetylcholine, or protamine, which have a high affinity for CX4 and are capable of entering cells, resulted in a fluorescence switch‐on response. This can be traced to the displacement of LCG from CX4 by the analytes. The results establish the principal functionality of indicator displacement assays with synthetic receptors for the detection of the uptake of bioorganic analytes by live cells.
“Post‐It” Type Connected DNA Created with a Reversible Covalent Cross‐Link
Authors: Tomás‐Gamasa María , Serdjukow Sascha , Su Meng , Müller Markus , Carell Thomas 
Published: November 2014

AbstractWe report the development of a new heterobase that is held together through reversible bonding. The so‐formed cross‐link adds strong stabilization to the DNA duplex. Despite this, the cross‐link opens and closes through reversible imine bonding. Moreover, even enzymatic incorporation of the cross‐link is possible. The new principle can be used to stabilize DNA duplexes and nanostructures that otherwise require high salt concentrations, which may hinder biological applications.
Interception of Cobalt‐Based Carbene Radicals with α‐Aminoalkyl Radicals: A Tandem Reaction for the Construction of β‐Ester‐γ‐amino Ketones
Authors: Zhang Jie , Jiang Jiewen , Xu Dongmei , Luo Qiang , Wang Hongxiang , Chen Jijun , Li Huihuang , Wang Yaxiong , Wan Xiaobing 
Published: November 2014

AbstractThe interception of cobalt‐based carbene radicals with α‐aminoalkyl radicals was combined with the Kornblum–DeLaMare reaction and provides β‐ester‐γ‐amino ketones, which are otherwise difficult to obtain in high chemoselectivity. Mechanistically, this transformation is an interplay of cobalt‐based carbene radicals, organoradicals, and ionic intermediates and involves the construction of two CC bonds and one CO bond in a one‐pot process. The reaction also features a wide substrate scope and is highly efficient and insensitive to moisture and air.
Solvation Dynamics of a Single Water Molecule Probed by Infrared Spectra—Theory Meets Experiment
Authors: Wohlgemuth Matthias , Miyazaki Mitsuhiko , Weiler Martin , Sakai Makoto , Dopfer Otto , Fujii Masaaki , Mitrić Roland 
Published: November 2014

AbstractThe dynamics and energetics of water at interfaces or in biological systems plays a fundamental role in all solvation and biological phenomena in aqueous solution. In particular, the migration of water molecules is the first step that controls the overall process in the time domain. Experimentally, the dynamics of individual water molecules is nearly impossible to follow in solution, because signals from molecules in heterogeneous environments overlap. Although molecular dynamics simulations do not have this restriction, there is a lack of experimental data to validate the calculated dynamics. Here, we demonstrate a new strategy, in which the calculated dynamics are verified by measured time‐resolved infrared spectra. The coexistence of fast and slow migrations of water molecules around a CONH peptide linkage is revealed for a model system representative of a hydrate peptide.
Total Synthesis of the Protected Aglycon of Fidaxomicin (Tiacumicin B, Lipiarmycin A3)
Authors: Miyatake‐Ondozabal Hideki , Kaufmann Elias , Gademann Karl 
Published: November 2014

AbstractFidaxomicin, also known as tiacumicin B or lipiarmycin A3, is a novel macrocyclic antibiotic that is used in hospitals for the treatment of Clostridium difficile infections. This natural product has also been shown to have excellent bactericidal activity against multidrug‐resistant Mycobacterium tuberculosis. In spite of its attractive biological activity, no total synthesis has been reported to date. The enantioselective synthesis of the central 18‐membered macrolactone is reported herein. The key reactions include ring‐closing metathesis between a terminal olefin and a dienoate moiety for macrocyclization, a vinylogous Mukaiyama aldol reaction, and a Stille coupling reaction of sterically demanding substrates. The retrosynthesis involves three medium‐sized fragments, thus leading to a flexible yet convergent synthetic route.
Nickel‐Catalyzed Dehydrogenative Cross‐Coupling: Direct Transformation of Aldehydes into Esters and Amides
Authors: Whittaker Aaron M. , Dong Vy M. 
Published: November 2014

AbstractBy exploring a new mode of nickel‐catalyzed cross‐coupling, a method to directly transform both aromatic and aliphatic aldehydes into either esters or amides has been developed. The success of this oxidative coupling depends on the appropriate choice of catalyst and organic oxidant, including the use of either α,α,α‐trifluoroacetophenone or excess aldehyde. Mechanistic data that supports a catalytic cycle involving oxidative addition into the aldehyde CH bond is also presented.
Hybrid Ruthenium ROMP Catalysts Based on an Engineered Variant of β‐Barrel Protein FhuA ΔCVFtev: Effect of Spacer Length
Authors: Sauer Daniel F. , Bocola Marco , Broglia Claudio , Arlt Marcus , Zhu Lei‐Lei , Brocker Melanie , Schwaneberg Ulrich , Okuda Jun 
Published: November 2014

AbstractA biohybrid ring‐opening olefin metathesis polymerization catalyst based on the reengineered β‐barrel protein FhuA ΔCVFtev was chemically modified with respect to the covalently anchored Grubbs–Hoveyda type catalyst. Shortening of the spacer (1,3‐propanediyl to methylene) between the N‐heterocyclic carbene ligand and the cysteine site 545 increased the ROMP activity toward a water‐soluble 7‐oxanorbornene derivative. The cis/trans ratio of the double bond in the polymer was influenced by the hybrid catalyst.
Short Protecting Group‐free Syntheses of Camptothecin and 10‐Hydroxycamptothecin Using Cascade Methodologies
Authors: Xu Peng , Chen Dong‐Sheng , Xi Jie , Yao Zhu‐Jun 
Published: November 2014

AbstractA convergent protecting group‐free total synthesis route of camptothecin and 10‐hydroxycamptothecin has been developed in this work. Cascade oxidation of 3‐(hydroxymethyl)furan‐2(5 H)‐one and in situ intermolecular oxa Diels–Alder reaction with vinyl ether was developed and applied to construct the E‐ring, and TMSCl‐promoted cascade closure of the D‐ring delivered the whole skeleton of the alkaloids in the total synthesis. The new short syntheses were advantageous with regard to step economy, low cost, easily available starting materials and reagents, and convenient operations.
Development and physiological characterization of cellobiose‐consuming Yarrowia lipolytica
Authors: Lane Stephan , Zhang Shuyan , Wei Na , Rao Christopher , Jin Yong‐Su 
Published: November 2014

ABSTRACTYarrowia lipolytica is a promising production host for a wide range of molecules, but limited sugar consumption abilities prevent utilization of an abundant source of renewable feedstocks. In this study we created a Y. lipolytica strain capable of utilizing cellobiose as a sole carbon source by using endogenous promoters to express the cellodextrin transporter cdt‐1 and intracellular β‐glucosidase gh1‐1 from Neurospora crassa. The engineered strain was also capable of simultaneous co‐consumption of glucose and cellobiose. Although cellobiose was consumed slower than glucose when engineered strains were cultured with excess nitrogen, culturing with limited nitrogen led to cellobiose consumption rates comparable to those of glucose. Under limited nitrogen conditions, the engineered strain produced citric acid as a major product and we observed greater citric acid yields from cellobiose (0.37 g/g) than glucose (0.28 g/g). Culturing with a sole carbon source of either glucose or cellobiose induced additional differences on cell physiology and metabolism and a link is suggested to evasion of glucose‐sensing mechanisms through intracellular creation and consumption of glucose. We ultimately applied this cellobiose‐utilization system to produce citric acid from bioconversion of crystalline cellulose through simultaneous saccharification and fermentation (SSF). Biotechnol. Bioeng. 2015;112: 1012–1022. © 2014 Wiley Periodicals, Inc.
A simple and low‐cost platform technology for producing pexiganan antimicrobial peptide in E. coli
Authors: Zhao Chun‐Xia , Dwyer Mirjana Dimitrijev , Yu Alice Lei , Wu Yang , Fang Sheng , Middelberg Anton P.J. 
Published: November 2014

ABSTRACTAntimicrobial peptides, as a new class of antibiotics, have generated tremendous interest as potential alternatives to classical antibiotics. However, the large‐scale production of antimicrobial peptides remains a significant challenge. This paper reports a simple and low‐cost chromatography‐free platform technology for producing antimicrobial peptides in Escherichia coli (E. coli). A fusion protein comprising a variant of the helical biosurfactant protein DAMP4 and the known antimicrobial peptide pexiganan is designed by joining the two polypeptides, at the DNA level, via an acid‐sensitive cleavage site. The resulting DAMP4var‐pexiganan fusion protein expresses at high level and solubility in recombinant E. coli, and a simple heat‐purification method was applied to disrupt cells and deliver high‐purity DAMP4var‐pexiganan protein. Simple acid cleavage successfully separated the DAMP4 variant protein and the antimicrobial peptide. Antimicrobial activity tests confirmed that the bio‐produced antimicrobial peptide has the same antimicrobial activity as the equivalent product made by conventional chemical peptide synthesis. This simple and low‐cost platform technology can be easily adapted to produce other valuable peptide products, and opens a new manufacturing approach for producing antimicrobial peptides at large scale using the tools and approaches of biochemical engineering. Biotechnol. Bioeng. 2015;112: 957–964. © 2014 Wiley Periodicals, Inc.
Particle Size Control and Crystal Habit Modification of Phenacetin Using Ultrasonic Crystallization
Authors: Su Chie‐Shaan , Liao Chieh‐Yun , Jheng Wun‐De 
Published: November 2014

AbstractPower ultrasound is applied for cooling crystallization to control and modify the particle size and crystal habit of an active pharmaceutical ingredient, phenacetin. Operating parameters including sonication intensity and duration, solution concentration, and cooling rate are studied and compared. With respect to mean particle size, the effect of sonication intensity is most significant. In addition, the crystal habit of recrystallized phenacetin is modified substantially and shows an elliptic shape. Recrystallized phenacetin also provides an enhanced dissolution rate compared with the original sample. These results prove that ultrasonic crystallization is an efficient tool for controlling the solid‐state properties of an active pharmaceutical ingredient.
Numerical Simulation of the Solute‐Induced Marangoni Effect with the Semi‐Lagrangian Advection Scheme
Authors: Chen Jie , Wang Zhihui , Yang Chao , Mao Zai‐Sha 
Published: November 2014

AbstractThe level set method is combined with the concentration transformation method to solve the interphase mass transfer process. However, the artificial diffusion generated in the mass transfer convection term across the interface is inevitable, especially when large shape deformation is encountered at high Reynolds numbers. A semi‐Lagrangian advection scheme is introduced to overcome this disadvantage. The methyl isobutyl ketone (MIBK)‐acetic acid‐water system is adopted to study the unsteady mass transport process accompanied with the Marangoni effect of a single deformable drop ascending in the infinite continuous phase. The predicted overall mass transfer coefficients agree with experimental data very well. The configuration of Marangoni convection is revealed and its effect on the interphase mass transfer process is investigated.