bluuebunny/crossref_metadata_2025_split huggingface dataset:
MAP Kinase cross talks in oxidative stress‐induced impairment of insulin secretion. Involvement in the protective activity of quercetin
Authors: Youl Estelle , Magous Richard , Cros Gérard , Oiry Catherine 
Published: April 2014

AbstractInsulin secretion preservation is a major issue for the prevention or treatment of type 2 diabetes. We previously showed on β‐cells that quercetin (Q), but not resveratrol (R) or N‐acetyl cysteine (NAC), amplified glucose‐induced insulin secretion in a calcium‐ and ERK1/2‐dependent manner. Quercetin, but not resveratrol or NAC, also protected β‐cell function and hyperamplified ERK1/2 phosphorylation in oxidative stress conditions. As quercetin may interfere with other stress‐activated protein kinases (JNK and p38 MAPK), we further explored MAPK cross talks and their relationships with the mechanism of the protective effect of quercetin against oxidative stress. In INS‐1 insulin‐secreting β‐cells, using pharmacological inhibitors of MAPK pathways, we found that under oxidative stress (50 μm H2O2) and glucose‐stimulating insulin secretion conditions: (i) p38 MAPK phosphorylation was increased and regulated by ERK1/2 (positively) and JNK (negatively), although p38 MAPK activation did not seem to play any significant role in oxidative stress‐induced insulin secretion impairment; (ii) the JNK pathway appeared to inhibit both ERK1/2 activation and insulin secretion, although JNK phosphorylation was not significantly changed in our experimental conditions; (iii) the functionality of β‐cell in the presence of oxidative stress was closely linked to the level of ERK1/2 activation, (iv) quercetin, resveratrol, or NAC inhibited H2O2‐induced p38 MAPK phosphorylation. The preservation of β‐cell function against oxidative stress appears dependent on the balance between ERK1/2 and JNK activation. The protecting effect of quercetin appears due to ERK1/2 hyperactivation, possibly induced by L‐type calcium channel opening as we recently showed (Br. J. Pharmacol. 2013, 169, 1102–1113).
Expression from engineered Escherichia coli chromosome and crystallographic study of archaeal N,N′‐diacetylchitobiose deacetylase
Authors: Mine Shouhei , Niiyama Mayumi , Hashimoto Wakana , Ikegami Takahisa , Koma Daisuke , Ohmoto Takashi , Fukuda Yohta , Inoue Tsuyoshi , Abe Yoshito , Ueda Tadashi , Morita Junji , Uegaki Koichi , Nakamura Tsutomu 
Published: April 2014

In order to develop a structure‐based understanding of the chitinolytic pathway in hyperthermophilic Pyrococcus species, we performed crystallographic studies on N,N′‐diacetylchitobiose deacetylases (Dacs) from Pyrococcus horikoshii (Ph‐Dac) and Pyrococcus furiosus (Pf‐Dac). Neither Ph‐Dac nor Pf‐Dac was expressed in the soluble fraction of Escherichia coli harboring the expression plasmid. However, insertion of the target genes into the chromosome of E. coli yielded the soluble recombinant protein. The purified Pyrococcus Dacs were active and thermostable up to 85 °C. The crystal structures of Ph‐Dac and Pf‐Dac were determined at resolutions of 2.0 Å and 1.54 Å, respectively. The Pyrococcus Dac forms a hexamer composed of two trimers. These Dacs are characterized by an intermolecular cleft, which is formed by two polypeptides in the trimeric assembly. In Ph‐Dac, catalytic Zn situated at the end of the cleft is coordinated by three side chain ligands from His44, Asp47, and His155, and by a phosphate ion derived from the crystallization reservoir solution. We considered that the bound phosphate mimicked the tetrahedral oxyanion, which is an intermediate of hydrolysis of the N‐acetyl group, and proposed an appropriate reaction mechanism. In the proposed mechanism, the Nε atom of His264 (from the adjacent polypeptide in the Ph‐Dac sequence) is directly involved in the stabilization of the oxyanion intermediate. Mutation analysis also indicated that His264 was essential to the catalysis. These factors give the archaeal Dacs an unprecedented active site architecture a Zn‐dependent deacetylases.DatabaseStructural data are available in the Protein Data Bank database under accession numbers 3WL3, 3WL4, and 3WE7.Structured digital abstractPh-Dac and Ph-Dac bind by x-ray crystallography (View interaction)Pf-Dac and Pf-Dac bind by x-ray crystallography (View interaction)
Amyloidogenic mutations in human apolipoprotein A‐I are not necessarily destabilizing – a common mechanism of apolipoprotein A‐I misfolding in familial amyloidosis and atherosclerosis
Authors: Das Madhurima , Mei Xiaohu , Jayaraman Shobini , Atkinson David , Gursky Olga 
Published: April 2014

High‐density lipoproteins and their major protein, apolipoprotein A‐I (apoA‐I), remove excess cellular cholesterol and protect against atherosclerosis. However, in acquired amyloidosis, nonvariant full‐length apoA‐I deposits as fibrils in atherosclerotic plaques; in familial amyloidosis, N‐terminal fragments of variant apoA‐I deposit in vital organs, damaging them. Recently, we used the crystal structure of Δ(185–243)apoA‐I to show that amyloidogenic mutations destabilize apoA‐I and increase solvent exposure of the extended strand 44–55 that initiates β‐aggregation. In the present study, we test this hypothesis by exploring naturally occurring human amyloidogenic mutations, W50R and G26R, within or close to this strand. The mutations caused small changes in the protein's α‐helical content, stability, proteolytic pattern and protein–lipid interactions. These changes alone were unlikely to account for amyloidosis, suggesting the importance of other factors. Sequence analysis predicted several amyloid‐prone segments that can initiate apoA‐I misfolding. Aggregation studies using N‐terminal fragments verified this prediction experimentally. Three predicted N‐terminal amyloid‐prone segments, mapped on the crystal structure, formed an α‐helical cluster. Structural analysis indicates that amyloidogenic mutations or Met86 oxidation perturb native packing in this cluster. Taken together, the results suggest that structural perturbations in the amyloid‐prone segments trigger α‐helix to β‐sheet conversion in the N‐terminal ~ 75 residues forming the amyloid core. Polypeptide outside this core can be proteolysed to form 9–11 kDa N‐terminal fragments found in familial amyloidosis. Our results imply that apoA‐I misfolding in familial and acquired amyloidosis follows a similar mechanism that does not require significant structural destabilization or proteolysis. This novel mechanism suggests potential therapeutic interventions for apoA‐I amyloidosis.Structured digital abstract

apoA-I and apoA-I bind by fluorescence technology (View interaction)

apoA-I and apoA-I bind by electron microscopy (View interaction)
Computerized and High‐Frequency Trading
Authors: Goldstein Michael A. , Kumar Pavitra , Graves Frank C. 
Published: April 2014

AbstractThe use of computers to execute trades, often with very low latency, has increased over time, resulting in a variety of computer algorithms executing electronically targeted trading strategies at high speed. We describe the evolution of increasingly fast automated trading over the past decade and some key features of its associated practices, strategies, and apparent profitability. We also survey and contrast several studies on the impacts of such high‐speed trading on the performance of securities markets. Finally, we examine some of the regulatory questions surrounding the need, if any, for safeguards over the fairness and risks of high‐speed, computerized trading.
Information Transmission between Financial Markets in Chicago and New York
Authors: Laughlin Gregory , Aguirre Anthony , Grundfest Joseph 
Published: April 2014

AbstractHigh‐frequency trading has led to widespread efforts to reduce information propagation delays between physically distant exchanges. Using relativistically correct millisecond‐resolution tick data, we document a three millisecond decrease in one‐way communication time between the Chicago and New York areas that occurred from April 27, 2010 to August 17, 2012. We attribute the first segment of this decline to the introduction of a latency‐optimized fiber optic connection in late 2010. A second phase of latency decrease can be attributed to line‐of‐sight microwave networks, operating primarily in the 6–11 GHz region of the spectrum, licensed during 2011 and 2012. Using publicly available information, we estimate these networks' latencies, costs, and bandwidths.
High‐Frequency Trading and the Execution Costs of Institutional Investors
Authors: Brogaard Jonathan , Hendershott Terrence , Hunt Stefan , Ysusi Carla 
Published: April 2014

AbstractThis paper studies whether high‐frequency trading (HFT) increases the execution costs of institutional investors. We use technology upgrades that lower the latency of the London Stock Exchange to obtain variation in the level of HFT over time. Following upgrades, the level of HFT increases. Around these shocks to HFT institutional traders’ costs remain unchanged. We find no clear evidence that HFT impacts institutional execution costs.
Comparison of 2 Equine Transfixation Pin Casts and the Effects of Pin Removal
Authors: Williams Jarred M. , Elce Yvonne A. , Litsky Alan S. 
Published: April 2014

ObjectiveTo (1) compare strain on the dorsal aspect of the proximal phalanx (P1) between 2 types of transfixation pin casts (TPC) and (2) evaluate the change in strain as the pins are removed.Study DesignExperimental.AnimalsEquine cadaver forelimbs (n = 10 pair).MethodsEach limb of a pair was assigned to 1 of 2 TPC constructs. Construct 1 consisted of a TPC with 2 positive profile, centrally threaded pins placed in the distal aspect of the third metacarpus (MC3) and construct 2 had 4 smooth Steinmann pins placed similarly. A strain gauge was mounted on P1 and axial compression (444.8–5337.9 N) applied. One forelimb of each pair was tested as a control with no construct in place. The 2 TPC groups were retested after removal of 1 proximal (n = 5 limbs) or distal (n = 5) pin from construct 1, and 2 proximal (n = 5) or distal (n = 5) pins from construct 2. Limb specimens were retested after all pins had been removed.ResultsThere was a significant decrease in strain between both TPC constructs and the non‐casted control at all loads except 444.8 N. There was no significant difference in strain reduction between the 2 TPC constructs. After proximal pin removal there was a 7% (construct 1) and 10% (construct 2) increase in strain. When distal pins were removed there was a 0.5% (construct 1) and 1% (construct 2) increase in strain. The difference between proximal and distal pin removal was only statistically different from each other at high loads.ConclusionBoth constructs provided equivalent reduction in strain. Removal of the proximal pin(s) increased the strain.
Pre‐death grief in the context of dementia caregiving: a concept analysis
Authors: Lindauer Allison , Harvath Theresa A. 
Published: April 2014

AbstractAimThe aim of this study was to report on an analysis of the concept of pre‐death grief in the context of dementia family caregiving.BackgroundResearch indicates that witnessing changes and losses in a family member with dementia can lead to pre‐death grief. Pre‐death grief is associated with depression, burden and maladaptive caregiver coping. However, the concept lacks a refined definition and blurs with similar constructs.DesignConcept analysis using a hybrid of Penrod and Hupcey's principle‐based concept analysis and Chin and Kramer's conceptualization of meaning.Data Sources49 peer‐reviewed papers (2000–2013) that addressed pre‐death grief in dementia family caregivers were used for the principle‐based analysis; two examples from the popular media were used for the analysis of conceptual meaning.MethodsThe scientific papers were examined for epistemological, linguistic, pragmatic and logical clarity. The two examples from the popular media were explored for conceptual meaning.ResultsPre‐death grief in the context of dementia caregiving is a meaningful concept found in the popular media. From a scholarly point of view, it is an emerging concept. A definition is offered to advance conceptual clarity. Discussion focuses on advancing the concept into a situation‐specific middle‐range theory of pre‐death grief in family caregiving.ConclusionsThe concept of pre‐death grief has salience for researchers and caregivers. This analysis lays the foundation for use of the concept in nursing research and practice across cultural, environmental and illness domains.
Filyos River Streamflow Reconstruction from Tree‐Ring Chronologies with Nonparametric Approaches
Authors: Şarlak Nermin 
Published: April 2014

AbstractThe article presents nonparametric methods based on K nearest neighbors (KNNs), modified KNNs, and local polynomial techniques to reconstruct streamflow ensembles from tree‐ring data in Filyos River region (Turkey). Three methods were tested using cross‐validation for the overlap period, 1963‐1997 for which the tree‐ring and streamflow data are available. It was found that for the study where the length of the overlap period was limited, a nonparametric method based on a local polynomial technique provides simulations that have a slightly better solution than the other methods. After verification using standard statistical techniques, these methods were utilized to develop streamflow reconstructions from tree‐ring data for the paleo‐hydrologic period (1657‐1963). These reconstructions of seasonal low and high flows were discussed with the obtained flood duration curve. They were also compared with the historical archives and other tree‐ring reconstructions data available in the same river. Overall, the utility and limitations of these methods and the resulting streamflow simulations were discussed to assess the long‐term discharge behavior of Filyos River and to evaluate water supply reliability.
Late Holocene range collapse in a former British seabird species
Authors: Brace Selina , Barnes Ian , Kitchener Andrew C. , Serjeantson Dale , Turvey Samuel T. 
Published: April 2014

AbstractAimTo determine the taxonomic identity of zooarchaeological gadfly petrel (Pterodroma) specimens from northern Europe, in order to investigate whether an unknown, now‐extinctPterodromaspecies formerly occurred in this region, or whether extant north‐east Atlantic gadfly petrel populations now restricted to the Macaronesian Islands formerly had a much wider Holocene distribution.LocationZooarchaeologicalPterodromamaterial from the Hebrides, Scotland, was compared with modern‐day material from the Madeira and Cape Verde archipelagos (Macaronesia) and a globalPterodromasample.MethodsWe employed techniques for ancientDNAanalysis to amplify mitochondrial cytochromebsequence data from an Iron Age ScottishPterodromaspecimen. Bayesian phylogenetic analyses were applied to assess the phylogenetic relationship between these ancient sequence data and extantPterodromataxa.ResultsThe ScottishPterodromasample is phylogenetically distinct from living Macaronesian populations and from all other extantPterodromataxa. Although it is phylogenetically placed outside any single Macaronesian taxon, it is most closely related to theP. feae–desertacomplex, and the level of sequence divergence between the ScottishPterodromaand Macaronesian populations is lower than that observed between any two extant globalPterodromataxa. The extinct north Atlantic gadfly petrels are therefore not distinct at the species level from these surviving populations, and instead form part of the young evolutionary radiation represented today by recently divergentPterodromapopulations on Bugio and Cape Verde, which can all be interpreted as conspecific.Main conclusionsOur results suggest that surviving MacaronesianP.feae–desertapopulations represent the final remnant of a wider Holocene distribution of this species complex, with the Madeira and Cape Verde archipelagos constituting the final sanctuary ofPterodromain the north Atlantic following late Holocene extirpation of more northerly colonies possibly associated with human‐mediated invasive mammal introduction across northern Europe. Macaronesia may therefore constitute a ‘museum’ of diversity rather than a ‘cradle’ of evolution for AtlanticPterodroma.
Tunnel technique with connective tissue graft versus coronally advanced flap with enamel matrix derivative for root coverage: a RCT using 3D digital measuring methods. Part II. Volumetric studies on healing dynamics and gingival dimensions
Authors: Rebele Stephan F. , Zuhr Otto , Schneider David , Jung Ronny E. , Hürzeler Markus B. 
Published: April 2014

AbstractAimThe aim of this randomized clinical trial (RCT) was to compare the clinical performance of the tunnel technique with subepithelial connective tissue graft (TUN) versus a coronally advanced flap with enamel matrix derivative (CAF) in the treatment of gingival recession defects. The use of innovative 3D digital measuring methods allowed to study healing dynamics at connective tissue (CT)‐grafted sites and to evaluate the influence of the thickness of the root covering soft tissues on the outcome of surgical root coverage.Material & MethodsTwenty‐four patients contributed a total of 47 Miller class I or II recessions for scientific evaluation. Precise study models collected at baseline and follow‐up examinations were optically scanned and virtually superimposed for digital evaluation of clinical outcome measures including mean marginal soft tissue thickness (THK). Healing dynamics were measured in a defined region of interest at CT‐grafted sites where volume differences between time points were calculated.ResultsAt 12 months, recession reduction as well as mean root coverage were significantly better at CT‐grafted sites treated in the TUN group (1.94 mm and 98.4% respectively) compared to the non‐augmented sites of the CAF group (1.17 mm and 71.8% respectively) and statistical analysis revealed a positive correlation of THK (1.63 mm TUN versus 0.91 mm CAF, p < 0.0001) to both these variables. Soft tissue healing following surgical root coverage with CT‐grafting was mainly accomplished after 6 months, with around two‐thirds of the augmented volume being maintained after 12 months.ConclusionsThe TUN resulted in thicker gingiva and better clinical outcomes compared to CAF. Increased gingival thickness was associated with better surgical outcomes in terms of recession reduction and root coverage.
Molecular Phylogeny and Ultrastructure of Caliculium glossobalani n. gen. et sp. (Apicomplexa) from a Pacific Glossobalanus minutus (Hemichordata) Confounds the Relationships Between Marine and Terrestrial Gregarines
Authors: Wakeman Kevin C. , Reimer James D. , Jenke‐Kodama Holger , Leander Brian S. 
Published: April 2014

AbstractGregarines are a diverse group of apicomplexan parasites with a conspicuous extracellular feeding stage, called a “trophozoite”, that infects the intestines and other body cavities of invertebrate hosts. Although the morphology of trophozoites is very diverse in gregarines as a whole, high degrees of intraspecific variation combined with relatively low degrees of interspecific variation make the delimitation of different species based on trophozoite morphology observed with light microscopy difficult. The coupling of molecular phylogenetic data with comparative morphology has shed considerable light onto the boundaries and interrelationships of different gregarine species. In this study, we isolated a novel marine gregarine from the hepatic region of a Pacific representative of the hemichordate Glossobalanus minutus, and report the first ultrastructural and molecular data from any gregarine infecting this distinctive group of hosts. Molecular phylogenetic analyses of an SSU rDNA sequence derived from two single‐cell isolates of this marine gregarine demonstrated a strong and unexpected affiliation with a clade of terrestrial gregarines (e.g. Gregarina). This molecular phylogenetic data combined with a comparison of the morphological features in previous reports of gregarines collected from Atlantic representatives of G. minutus justified the establishment of a new binomial for the new isolate, namely Caliculium glossobalani n. gen. et sp. The molecular phylogenetic analyses demonstrated a clade of terrestrial gregarines associated with a sequence acquired from a marine species, which suggest that different groups of terrestrial/freshwater gregarines evolved independently from marine ancestors.
Trans‐Free Nondairy Creamer Prepared from Enzymatic Interesterification of Soybean Oil and Fully Hydrogenated Soybean Oil
Authors: Wang Biao , Liu Jie 
Published: April 2014

AbstractTrans‐free fats were prepared from enzymatic interesterification of soybean oil (SO) and fully hydrogenated soybean oil (FHSBO) and the fats were used as core material to prepare nondairy creamer. The method of preparation and characteristics of nondairy creamer had been studied. The obtained products were evaluated for their physicochemical characteristics that included moisture content, peroxide value, acid value and bulk density, and were proved to have no significant difference with commercial products. Nondairy creamer prepared in this study was trans‐free (<0.1%) in comparison with over 30% Trans Fatty Acids content of commercial products. The present study can be used as a method to prepare trans‐free nondairy creamer and make this kind of products healthier.Practical ApplicationsNondairy creamer is widely used in food industry for its economy, good antioxidant capacity, being easily dissolved in water, ease of handling and improved shelf life. But commercial products have high content of trans‐fatty acids that are harmful to people's health. In consideration of this, preparing trans‐free nondairy creamer is significant to consumers' health and food industry. SO and FHSBO were trans‐free. In the process of interesterification of these two kinds of oil, the fatty acids were recombined and its structure did not change, which made the final reaction products trans‐free and healthier. Consequently, the reaction products can be used as core material to prepare trans‐free nondairy creamer, and the final products can get acceptable sensory qualities.
IS FINANCIAL SUPPORT FOR PRIVATE R&D ALWAYS JUSTIFIED? A DISCUSSION BASED ON THE LITERATURE ON GROWTH
Authors: Montmartin Benjamin , Massard Nadine 
Published: April 2014

AbstractMany economists have long held that market failures create a gap between social and private returns to research and development (R&D), thereby limiting private incentives to invest in R&D. However, this common belief that firms significantly underinvest in R&D is increasingly being challenged, leading the rationale behind public support for private R&D to be questioned. In this paper, we attempt to clarify the perspectives of two sources: the theoretical literature on endogenous growth, and its recent developments in integrating a geographical dimension, and the empirical literature that measures the social returns to R&D in relation to the private returns. Ultimately, we are able to clearly distinguish among different types of market failures and compare their relative impact on the gap between the private and social returns to R&D. Two main conclusions are reached. First, systematic firm underinvestment in R&D is not demonstrated. Second, even though instances of underinvestment do occur, they are mainly explained by surplus appropriability problems rather than by knowledge externalities. This suggests the need for a new policy mix that employs more demand‐oriented instruments and is more concentrated on identifying efficient allocations among activities rather than merely increasing global private R&D investment.