bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence for inhibitory autocrine effects of proinsulin C‐peptide on pancreatic β‐cell function and insulin secretion
Authors: McKillop A. M. , Ng M. T. , Abdel‐Wahab Y. H. A. , Flatt P. R. 
Published: April 2014

AimsAutocrine and paracrine regulatory mechanisms ensure integrated secretion of islet hormones that respond efficiently to changes in metabolic need. As proinsulin C‐peptide exerts various biological effects and binds to cell membranes including insulin‐secreting β cells, its physiological role in insulin release was examined.MethodsInsulin releasing activity of human and rat C‐peptides were studied in the clonal pancreatic cell line, BRIN‐BD11, with findings substantiated using isolated islets and in vivo studies employing SWISS TO mice.ResultsAcute exposure of clonal β cells to human C‐peptide resulted in concentration‐dependent inhibitory effects on insulin secretion at 5.6 mM (p < 0.05–p < 0.001) and 16.7 mM (p < 0.01–p < 0.001) glucose. At physiologically relevant intra‐islet concentrations (10−9–10−6 M), C‐peptide suppressed the insulin‐secretory responses to a range of secretagogues acting at different points in the β cell stimulus‐secretion coupling pathway including alanine (p < 0.05), Ca2+ (p < 0.001), arginine (p < 0.05), tolbutamide (p < 0.001), glucagon‐like peptide 1 (GLP‐1) (p < 0.001), isobutylmethylxanthine (IBMX) (p < 0.01) and KCl (p < 0.05). Similar results were obtained using isolated mouse pancreatic islets. Human C‐peptide (3 × 10−7 M, p < 0.001), somatostatin‐14 (3 × 10−7 M, p < 0.01) and diazoxide (300 µM, p < 0.001) reduced both alanine and glucose‐stimulated insulin release by 43, 25 and 48%, respectively. The effects of human C‐peptide were reproduced using rat C‐peptide I and II. C‐peptide also inhibited in vivo glucose‐stimulated insulin release and impaired glucose tolerance in mice.ConclusionsC‐peptide is a biologically active endogenous peptide hormone that exerts inhibitory autocrine effects on pancreatic β‐cell function. Mechanisms involving the activation of K+ channels and a distal effect downstream of increased cytoplasmic Ca2+ appear to be implicated in the inhibition of insulin secretion.
Structural characterization of CspZ, a complement regulator factor H and FHL‐1 binding protein from Borrelia burgdorferi
Authors: Brangulis Kalvis , Petrovskis Ivars , Kazaks Andris , Bogans Janis , Otikovs Martins , Jaudzems Kristaps , Ranka Renate , Tars Kaspars 
Published: April 2014

Borrelia burgdorferi is the causative agent of Lyme disease and is found in two different types of hosts in nature – Ixodes ticks and various mammalian organisms. To initiate disease and survive in mammalian host organisms, B. burgdorferi must be able to transfer to a new host, proliferate, attach to different tissue and resist the immune response. To resist the host's immune response, B. burgdorferi produces at least five different outer surface proteins that can bind complement regulator factor H (CFH) and/or factor H‐like protein 1 (CFHL‐1). The crystal structures of two uniquely folded complement binding proteins, which belong to two distinct gene families and are not found in other bacteria, have been previously described. The crystal structure of the CFH and CFHL‐1 binding protein CspZ (also known as BbCRASP‐2 or BBH06) from B. burgdorferi, which belongs to a third gene family, is reported in this study. The structure reveals that the overall fold is different from the known structures of the other complement binding proteins in B. burgdorferi or other bacteria; this structure does not resemble the fold of any known protein deposited in the Protein Data Bank. The N‐terminal part of the CspZ protein forms a four‐helix bundle and has features similar to the FAT domain (focal adhesion targeting domain) and a related domain found in the vinculin/α‐catenin family. By combining our findings from the crystal structure of CspZ with previous mutagenesis studies, we have identified a likely binding surface on CspZ for CFH and CFHL‐1.
When Finance Meets Physics: The Impact of the Speed of Light on Financial Markets and Their Regulation
Authors: Angel* James J. 
Published: April 2014

AbstractModern physics has demonstrated that matter behaves very differently as it approaches the speed of light. This paper explores the implications of modern physics to the operation and regulation of financial markets. Information cannot move faster than the speed of light. The geographic separation of market centers means that relativistic considerations need to be taken into account in the regulation of markets. Observers in different locations may simultaneously observe different “best” prices. Regulators may not be able to determine which transactions occurred first, leading to problems with best execution and trade‐through rules. Catastrophic software glitches can tunnel through seemingly impregnable quality control procedures.
High‐Frequency Traders and Market Structure
Authors: Menkveld Albert J. 
Published: April 2014

AbstractThe arrival of high‐frequency traders (HFTs) coincided with the entry of new markets and, subsequently, strong fragmentation of the order flow. These trends might be related as new markets serve HFTs who seek low fees and high speed. New markets only thrive on competitive price quotes that well‐connected HFTs can deliver as they can offload any nonzero position in any market they are connected to. HFTs may benefit or hurt market quality through adverse selection on price quotes, a technology arms race, or high‐risk trading strategies.
Net change in carbon emissions with increased wood energy use in the United States
Authors: Nepal Prakash , Wear David N. , Skog Kenneth E. 
Published: April 2014

AbstractUse of wood biomass for energy results in carbon (C) emissions at the time of burning and alters C stocks on the land because of harvest, regrowth, and changes in land use or management. This study evaluates the potential effects of expanded woody biomass energy use (for heat and power) on net C emissions over time. A scenario with increased wood energy use is compared with a dynamic business‐as‐usual scenario where wood energy use is driven by its historical relationship with gross domestic product. At the national level, we projected that up to 78% of increased cumulative C emissions from increased wood burning and up to 80% of increased cumulative radiative forcing would be offset over 50 years by change in forest area loss, biomass regrowth on land, C storage in harvested wood products, and C in logging slash left in forests. For example, forest area is projected to decline in both scenarios, but 3.5 million hectares more are retained in the high wood energy‐use case. Projected C offsets over a 50 year period differed substantially by US region (16% in the North, 50% in the West, and 95% in the South) not only because of differences in forest regrowth and induced investment in retaining and planting forest, but also because of shifts in competitive advantage among regions in producing various wood products. If wood systems displace coal systems that have 75% of the C emissions of wood energy systems per unit energy, then the nationwide net C emissions offset would be reduced to 71–74%. If displacing natural gas systems that have 40% of the level of wood bioenergy emissions per unit energy, the nationwide net C emissions offset would be 46–52%.
Biomechanical Testing of a Novel Tendon Implant Device for the Repair of Equine Flexor Tendon Lacerations
Authors: Barrett Elizabeth J. , Munsterman Amelia S. , Hanson R. Reid , Jackson Robert L. 
Published: April 2014

ObjectiveTo comparein vitrostrength and failure characteristics of a tendon implant against a 3 loop pulley suture pattern for equine superficial digital flexor tendon (SDFT) laceration repair.Study DesignExperimental.Study PopulationCadaveric equine forelimb SDFT (n = 16).MethodsOne tendon of each of 8 pair of SDFT was randomly selected for repair with either the 3‐loop pulley (3LP) suture pattern using 2 polydioxanone or with 4 stainless steel suture and anchor implants (SA). Ultimate load to failure, mode of failure, gap at failure, and load to 2 mm gap were obtained using a materials testing system synchronized with a high‐speed camera. Statistical evaluation was made using Student'st‐test; significance was set atP ≤ .05.ResultsThe 3LP failed at a significantly (P = .0001) greater load (363.5 ± 83.7 N) than SA (132.4 ± 26.8 N), but the load to a 2 mm gap (3LP = 164.9 ± 67.7 N, SA = 114.5 ± 21.5 N) was not significantly different (P = .09). Failure mode was by suture pull out and anchor pull out respectively. The gap at failure was significantly larger in the 3LP than in SA repair (P = .000005).ConclusionsBoth the SA repair and the 3LP resisted similar tension to 2 mm gap. However, the ultimate load to failure of the SA repair was only 36% that of the 3LP repair.
Aliskiren‐attenuated myocardium apoptosis via regulation of autophagy and connexin‐43 in aged spontaneously hypertensive rats
Authors: Zhang Wenbin , Zhao Gang , Hu Xiaona , Wang Min , Li Hua , Ye Yong , Du Qijun , Yao Jin , Bao Zhijun , Hong Wei , Fu Guosheng , Ge Junbo , Qiu Zhaohui 
Published: April 2014

AbstractThere are controversies about the mechanism of myocardium apoptosis in hypertensive heart disease. The aim of this study was to investigate the relationship among autophagy, Cx43 and apoptosis in aged spontaneously hypertensive rats (SHRs) and establish whether Aliskiren is effective or not for the treatment of myocardium apoptosis. Twenty‐one SHRs aged 52 weeks were randomly divided into three groups, the first two receiving Aliskiren at a dose of 10 and 25 mg/kg/day respectively; the third, placebo for comparison with seven Wistar‐Kyoto (WKY) as controls. After a 2‐month treatment, systolic blood pressure (SBP), heart to bw ratios (HW/BW%) and angiotensin II (AngII) concentration were significantly enhanced in SHRs respectively. Apoptotic cardiomyocytes detected with TUNEL and immunofluorescent labelling for active caspase‐3 increased nearly fourfolds in SHRs, with a decline in the expression of survivin and AKT activation, and an increase in caspase‐3 activation and the ratio of Bax/Bcl‐2. Myocardium autophagy, detected with immunofluorescent labelling for LC3‐II, increased nearly threefolds in SHRs, with the up‐regulation of Atg5, Atg16L1, Beclin‐1 and LC3‐II. The expression of Cx43 plaque was found to be down‐regulated in SHRs. Aliskiren significantly reduced SBP, HW/BW%, AngII concentration and the expression of AT1R. Thus, Aliskiren protects myocardium against apoptosis by decreasing autophagy, up‐regulating Cx43. These effects showed a dose‐dependent tendency, but no significance. In conclusion, the myocardium apoptosis developed during the hypertensive end‐stage of SHRs could be ameliorated by Aliskiren via the regulation of myocardium autophagy and maladaptive remodelling of Cx43.
A Generic Method for Determining Moisture Sorption Isotherms of Cereal Grains and Legumes Using Artificial Neural Networks
Authors: Al‐Mahasneh Majdi , Alkoaik Fahad , Khalil Ahmed , Al‐Mahasneh Ahmad , El‐Waziry Ahmed , Fulleros Ronnel , Rababah Taha 
Published: April 2014

AbstractMoisture sorption isotherms (MSI) are required to optimize handling, drying, processing and storage of food products. MSI are obtained by solving nonlinear equations iteratively, which is normally a difficult process. A generic approach was successfully used for collective prediction of MSI for 12 cereals and five legumes simultaneously, by taking advantage of the superior computational capabilities of artificial neural networks (ANNs). A total of 779 observations were collected from literature and used in training and validation of ANNs. The ANNs model used product type (grains or legumes), sorption state (adsorption or desorption), temperature and equilibrium moisture content as inputs to predict equilibrium relative humidity. A one‐ and two‐hidden‐layer ANNs were implemented. The overall prediction results obtained from ANNs were found to compare well with those reported for conventional analytical MSI models. The average prediction results obtained from the two‐hidden‐layer ANN for mean square error, deviation modulus and R2 were 0.009, 4.47% and 0.984, respectively. The results for each product compared well with those obtained from analytical MSI models. Four important issues that are commonly raised when implementing ANNs in prediction of MSIs were explained. These included preventing network over‐fitting, minimizing the time and effort needed for ANN architecture optimization, validating reproducibility of the results and validating the network capability to predict new observations. Unlike conventional MSI models, ANNs used the same network to predict MSIs for several products simultaneously. The principle can be easily expanded to predict MSI for other larger sets of various products, which can save time and effort.Practical ApplicationsDetermination of moisture sorption isotherms (MSI) is required for optimization of grain drying, processing, handling and storage operations. They can be also used to evaluate theoretical drying energy requirements and optimum storage conditions for a specific food product. In addition, they are used in food engineering calculations related to equipment design, shelf life evaluation and stability during storage operations. Determination of MSI for food products involves the use of conventional nonlinear MSI models, which requires an iterative solution methodology. The results are also specific to the food product investigated. Artificial neural networks were therefore proposed in this study as an alternative method for the collective prediction of MSI for some cereal grains and legumes. The method proposed in the study was accurate and reliable. In addition, it can be extended to larger varieties of food materials.
Benefit of Cone‐Beam CT Angiography in Visualizing Aneurysm Shape and Identification of Exact Rupture Site
Authors: Lauric Alexandra , Heller Robert S. , Schimansky Sarah , Malek Adel M. 
Published: April 2014

ABSTRACTWhile high‐resolution cone‐beam computational tomographic (CBCT) angiography has gained use in intracranial vascular imaging, digital subtraction angiography (DSA) and 3‐dimensional‐rotational angiography (3D‐RA) remain the preferred acquisition modalities for intracranial aneurysm imaging. This case report highlights the utility of the greater spatial resolution afforded by CBCT for cerebral aneurysm imaging. A 54‐year‐old man presenting with subarachnoid hemorrhage was confirmed to harbor a ruptured anterior communicating artery aneurysm by conventional angiography. Due to varying contrast opacification captured by different acquisition methods, dramatic aneurysm shape difference was observed between 2‐ and 3‐dimensional‐angiographic and CBCT models. The greater resolution of CBCT revealed in an unequivocal fashion the exact site of rupture on the aneurysm dome, visualized as a discrete irregular and elongated bleb that was not seen on either 3D‐RA or DSA. High‐resolution CBCT visualized the shape of the target aneurysm in greater detail than the more conventional 2D‐DSA and 3D‐RA, enabling more precise computational fluid dynamics (CFD) simulations. Given that aneurysms most likely change shape either prior to rupture or upon rupture, future studies evaluating fluid dynamics using computer reconstructions should be cognizant of the differences in resolution provided by various imaging modalities.
Plant species richness of very small forests related to patch configuration, quality, heterogeneity and history
Authors: Wulf Monika , Kolk Jens 
Published: April 2014

AbstractQuestions(i) Is plant species richness related to patch configuration, quality, heterogeneity and history in very small forest patches? (ii) Is there a similar effect of patch configuration, quality, heterogeneity and history on all plant species or does it vary for different plant groups? (iii) Does the importance of patch configuration, quality, heterogeneity and history vary for plant species richness between patch size classes?LocationPrignitz region, western part of Brandenburg, GermanyMethodsPlant species lists for 183 forest patches (0.08–12.7 ha) were compiled. We conducted a hierarchical partitioning analysis to test which of the four patch variables – configuration, quality, heterogeneity and history – explained most of the variance in plant species richness and richness of various plant groups.ResultsIrrespective of patch size class, species richness is mainly predicted by patch quality and heterogeneity. In particular, generalists are primarily affected by the soil moisture and nutrient level, and specialists additionally by patch heterogeneity and history. A higher historical habitat quality, together with long habitat continuity, led to an increase in forest specialists and geophytes in all patches. In the >5‐ha patches only historical habitat quality accounted for a significant increase in the number of species with short‐distance dispersal capacity in all species. Regardless of patch size, the number of locally infrequent species increased significantly with historical habitat quality. The effect of patch configuration was negligible, except for space‐filling trees and shrubs, when considering all patches.ConclusionsOur more comprehensive statistical approach shows, in general, that all complex variables have an effect on species richness and should be considered in future studies. The fact that patch heterogeneity and quality are the main predictors of species richness indicates that very small forest patches covered a range of highly structured patches and sites having various growth conditions. We assume that the century‐old tradition of private ownership with smallholder social structure is the main reason for variability in stand structure and species assemblage, resulting in the uniqueness of each patch. Since the number of locally infrequent plant species increases significantly with historical habitat quality, we suggest that it is particularly important to consider this variable in future studies on the decline of infrequent plant species.
Effects of Muscari comosum Extract on Nonspecific Immune Parameters in Gilthead Seabream, Sparus aurata (L. 1758)
Authors: Baba Esİn , Uluköy Gülşen , Mammadov Ramazan 
Published: April 2014

AbstractThis study was conducted to determine the effects of Muscari comosum (L.) Mill. 1768, geophyte plant extract on some nonspecific immune parameters of gilthead seabream, Sparus aurata (L. 1758). For this purpose, the plant was collected and extracted in ethanol solvent. Three different fish groups were formed, and each group was duplicated (total 300 fish). The plant extract was applied to the fish by intraperitoneal injection in two different concentrations (0.5 mg/fish and 2 mg/fish). Following injections on the 1st, 7th, 14th, 21st, and 28th d, blood samples were collected from each group. Some of the nonspecific immune parameters in blood and serum samples such as leukocyte level, phagocytic activity (NBT (+) cells), lysozyme activity, and the percentage of white blood cells were determined. The results indicate that in line with the parameters observed, the group given 0.5 mg/fish was not as effective as the one given 2 mg/fish but more effective than the control group. The nonspecific immune parameters of blood samples of the gilthead seabream in the 2 mg/fish experimental group showed that maximum levels on measured parameters of blood were reached at the first week postinjection. The applied concentrations of plant extract did not inhibit growth performance in any of the groups.
Effect of Dietary N‐acyl Homoserin Lactonase on the Immune Response and the Gut Microbiota of Zebrafish, Danio rerio, Infected with Aeromonas hydrophila
Authors: Cao Yanan , Liu Yuchun , Mao Wei , Chen Ruidong , He Suxu , Gao Xiuhua , Zhou Zhigang , Yao Bin 
Published: April 2014

AbstractQuorum sensing interference is a novel strategy in bacterial disease control. Degradation of quorum sensing signal molecules, such as N‐acyl homoserine lactones (AHLs), by enzymes is a potential interfering method. In this study, the in vivo effect of an N‐acyl homoserine lactonase from Bacillus sp. B546, AiiAB546, on the protection of zebrafish, Danio rerio, against Aeromonas hydrophila infection was first investigated by co‐feeding. The short‐term immune responses and the long‐term effects on the gut microbiota of zebrafish were analyzed by quantitative polymerase chain reaction (qPCR) and denaturing gradient gel electrophoresis (DGGE), respectively. The results showed that the expression levels of some anti‐infectious immunity‐related factors, including interleukin 10 (IL‐10), toll‐like receptor 5b (TLR5b), and inducible nitric oxide synthase 2a (iNOS2a) that were related to A. hydrophila virulent factors under regulation of quorum sensing, were more susceptible to the addition of AiiAB546. It indicated that AiiAB546 may attenuate the infection of A. hydrophila by interfering with quorum sensing. A. hydrophila was not detected in the enzyme co‐feeding diet group, which might be due to its inability to adhere to the gut with enzyme interference. This study revealed that AiiAB546 as a feed additive might represent a novel biocontrol agent in aquaculture; however, the topic merits further investigations using fish species of commercial interest.
Molecular Characteristic and Responsive Expression of Arginine Kinase in the Mud Crab, Scylla paramamosain
Authors: Xie Yinjie , Gong Jie , Ye Haihui , Huang Huiyang , Yang Ya'nan 
Published: April 2014

AbstractArginine kinase (AK) is a phosphor‐transferase which plays a critical role in energy metabolism in invertebrates. Using reverse transcription‐polymerase chain reaction (RT‐PCR) and rapid amplification of cDNA ends (RACE) PCR, this study successfully cloned a 1469 bp full‐length complementary DNA (cDNA) of AK from the mud crab, Scylla paramamosain (designated as SpAK). The open‐reading frame (ORF) of SpAK was 1071 bp, encoding 357 amino acids. The predicted protein showed a high level of identity to known AK from other invertebrates and creatine kinase (CK) from vertebrates that belongs to a conserved family of ATP: guanidine phosphotransferases. The SpAK gene contains two exons and one intron. The quantitative real‐time PCR analysis revealed a broad expression of SpAK in various tissues. After challenge with the bacterium Vibrio alginolyticus, the peak value of AK expression in hepatopancreas increased 17‐fold (at 3 h), and 15‐fold (at 72 h) in hemolymph, as compared to the control. The present research suggests that AK might be involved in immune response of the mud crab, S. paramamosain.