bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Photoexcitation Energy Dependence in the Photoluminescence of Firefly Luciferin
Authors: Hiyama Miyabi , Akiyama Hidefumi , Mochizuki Toshimitsu , Yamada Kenta , Koga Nobuaki 
Published: January 2014

AbstractThe whole pathways for photoluminescence, which include absorption, relaxation and emission, of firefly luciferin in aqueous solutions of different pH values with different photoexcitation energies were theoretically investigated by considering protonation/deprotonation. It is experimentally known that the color of fluorescence changes from green to red with a decrease in the photoexcitation energy. We confirmed with the theoretical analysis that the peak energy shift in the fluorescence spectra with varying photoenergies is due to a change in photoluminescence pathway. When the photoexcitation energy is decreased, the red emission from a monoanion form of firefly luciferin with carboxylate and phenolate groups and N‐protonated thiazoline ring occurs irrespective of the pH values. However, because the species abundant in the solution and those excited by the photon depend on the solution pH, the pathway leading to the monoanion form changes with the solution pH.
Chronic Trypanosoma congolense infections in mice cause a sustained disruption of the B‐cell homeostasis in the bone marrow and spleen
Authors: Obishakin E. , de Trez C. , Magez S. 
Published: January 2014

SummaryTrypanosoma congolense is one of the main species responsible for Animal African Trypanosomosis (AAT). As preventive vaccination strategies for AAT have been unsuccessful so far, investigating the mechanisms underlying vaccine failure has to be prioritized. In T. brucei and T. vivax infections, recent studies revealed a rapid onset of destruction of the host B‐cell compartment, resulting in the loss of memory recall capacity. To assess such effect in experimental T. congolense trypanosomosis, we performed infections with both the cloned Tc13 parasite, which is considered as a standard model system for T. congolense rodent infections and the noncloned TRT55 field isolate. These infections differ in their virulence level in the C57BL/6 mouse model for trypanosomosis. We show that early on, an irreversible depletion of all developmental B cells stages occur. Subsequently, in the spleen, a detrimental decrease in immature B cells is followed by a significant and permanent depletion of Marginal zone B cells and Follicular B cells. The severity of these events later on in infection correlated with the virulence level of the parasite stock. In line with this, it was observed that later‐stage infection‐induced IgGs were largely nonspecific, in particular in the more virulent TRT55 infection model.
Trade and the Speed of Convergence
Authors: Song E. Young 
Published: January 2014

AbstractNumerous studies on income convergence estimate the convergence equation derived for autarkic economies using data from the world that is increasingly integrated. This paper derives a convergence equation for a world integrated by trade from the standard Heckscher–Ohlin model with factor price equalization. The convergence equation for an integrated world differs from the autarkic one in that (1) the growth rate of each economy is increasing in the global growth rate; (2) the rate of convergence is increasing in the global growth rate; and (3) the rate of convergence, under conventional parameter values, is much lower.
The Growth and Decline of the Modern Sector and the Merchant Class in Imperial China
Authors: Chan Kenneth S. , Laffargue Jean‐Pierre 
Published: January 2014

AbstractThis paper offers an explanation of why, in Imperial China, the merchant class expanded and the economy modernized up to the 13th century, and why it entered into decline from the 14th century onward. The modernization of China required the accumulation of public capital and the building of good institutions, upon which a vibrant class of merchants and entrepreneurs could gradually emerge. This class contributed to the enrichment of the society and the emperor, but its activities also weakened the dominance of the emperor and the élite, who would then prefer to block the modernization of China and to restrict the size of the merchant class, putting the economy into long‐run stagnation. However, when the emperor faced severe foreign military threats and when he realized that a modern sector improved the defense capabilities of China, he made the opposite choice.
Offshoring and Firm Performance: Evidence from the Italian Manufacturing Industry
Authors: D'Attoma Ida , Pacei Silvia 
Published: January 2014

AbstractThe fundamental question of whether offshoring is value enhancing and, more specifically, whether Italian manufacturing firms that undertake offshoring benefit from higher productivity and profitability is explored. Using data from the tenth wave of the “Survey on Manufacturing Firms” conducted by Unicredit‐Capitalia, it was found that, compared with domestic firms, firms relocating activities to a foreign country have different characteristics, and “better” firms might self‐select into offshoring decision. To disentangle the effect of offshoring on firms' performances from the effect of firm characteristics, several variants of propensity score matching are used. A mild and insignificant positive effect of offshoring on profitability was found and also evidence of a statistically significant positive effect of offshoring on productivity.
Globalization, Ownership Structures and Productivity Dispersion
Authors: Kim Sung‐min , Hwang Jin‐tae 
Published: January 2014

AbstractWe investigate the heterogeneous effects of productivity dispersion on firms' organizational choices, depending upon sectoral characteristics. Using trade data on imports from non‐related parties (outsourcing) and related parties (integration) in the South, we show that productivity dispersion would increase imports from the South with outsourcing in the low headquarter intensity sector, along with an increasing fraction of the intra‐firm imports in the high headquarter intensity sector, which is consistent with the predictions from the theory. Considering the bounded nature of a share of the intra‐firm imports, a quasi‐maximum likelihood estimation was used.
Experimental and Numerical Post‐buckling Analysis of Thin Aluminium Aeronautical Panels under Shear Load
Authors: Cricrì G. , Perrella M. , Calì C. 
Published: January 2014

ABSTRACTIn this work, a novel multi‐hinged test fixture, which can apply a pure shear load to thin panels, is presented. The new device has been used to perform several experimental tests on the shear behaviour of aluminium alloy panels. Four different test configurations have been considered: stiffened and not stiffened panels, with and without a central rectangular cut‐out. The specimens, made of Al 6082 T6, are tested under shear load boundary conditions up to buckling and post‐buckling occurrence. Furthermore, finite element analyses have been performed in order to simulate the four panel configurations tests. The new test fixture has shown the capability to buckle a panel attaining very large out‐of‐plane displacements, if compared to the outcomes of a traditional picture frame test fixture, under the same external load. Numerical and experimental results are finally compared, showing a satisfactory agreement.
HLA typing by next‐generation sequencing – getting closer to reality
Authors: Gabriel C. , Fürst D. , Faé I. , Wenda S. , Zollikofer C. , Mytilineos J. , Fischer G. F. 
Published: January 2014

AbstractNext generation sequencing (NGS) denotes novel sequencing technologies that enable the generation of a large number of clonal sequences in a single sequencing run. NGS was initially introduced for whole genome sequencing and for quantitation of viral variants or genetic mutations in tumor tissues; more recently, the potential for high resolution HLA typing and high throughput analyses has been explored. It became clear that the complexity of the HLA system implicates new challenges, especially for bioinformatics. From an economical point of view, NGS is becoming increasingly attractive for HLA typing laboratories currently relying on Sanger based sequencing. Realizing the full potential of NGS will require the development of specifically adapted typing strategies and software algorithms. In the present review, three laboratories that were among the first to perform HLA‐typing using different NGS platforms, the Roche 454, the Illumina Miseq and the Ion Torrent system, respectively, give an overview of these applications and point out advantages and limitations.
Biosynthesis, elicitation and roles of monocot terpenoid phytoalexins
Authors: Schmelz Eric A. , Huffaker Alisa , Sims James W. , Christensen Shawn A. , Lu Xuan , Okada Kazunori , Peters Reuben J. 
Published: January 2014

SummaryA long‐standing goal in plant research is to optimize the protective function of biochemical agents that impede pest and pathogen attack. Nearly 40 years ago, pathogen‐inducible diterpenoid production was described in rice, and these compounds were shown to function as antimicrobial phytoalexins. Using rice and maize as examples, we discuss recent advances in the discovery, biosynthesis, elicitation and functional characterization of monocot terpenoid phytoalexins. The recent expansion of known terpenoid phytoalexins now includes not only the labdane‐related diterpenoid superfamily but also casbane‐type diterpenoids and β‐macrocarpene‐derived sequiterpenoids. Biochemical approaches have been used to pair pathway precursors and end products with cognate biosynthetic genes. The number of predicted terpenoid phytoalexins is expanding through advances in cereal genome annotation and terpene synthase characterization that likewise enable discoveries outside the Poaceae. At the cellular level, conclusive evidence now exists for multiple plant receptors of fungal‐derived chitin elicitors, phosphorylation of membrane‐associated signaling complexes, activation of mitogen‐activated protein kinase, involvement of phytohormone signals, and the existence of transcription factors that mediate the expression of phytoalexin biosynthetic genes and subsequent accumulation of pathway end products. Elicited production of terpenoid phytoalexins exhibit additional biological functions, including root exudate‐mediated allelopathy and insect antifeedant activity. Such findings have encouraged consideration of additional interactions that blur traditionally discrete phytoalexin classifications. The establishment of mutant collections and increasing ease of genetic transformation assists critical examination of further biological roles. Future research directions include examination of terpenoid phytoalexin precursors and end products as potential signals mediating plant physiological processes.
Light‐dependent reversible phosphorylation of the minor photosystem II antenna Lhcb6 (CP24) occurs in lycophytes
Authors: Ferroni Lorenzo , Angeleri Martina , Pantaleoni Laura , Pagliano Cristina , Longoni Paolo , Marsano Francesco , Aro Eva‐Mari , Suorsa Marjaana , Baldisserotto Costanza , Giovanardi Martina , Cella Rino , Pancaldi Simonetta 
Published: January 2014

SummaryEvolution of vascular plants required compromise between photosynthesis and photodamage. We analyzed representative species from two divergent lineages of vascular plants, lycophytes and euphyllophytes, with respect to the response of their photosynthesis and light‐harvesting properties to increasing light intensity. In the two analyzed lycophytes, Selaginella martensii and Lycopodium squarrosum, the medium phase of non‐photochemical quenching relaxation increased under high light compared to euphyllophytes. This was thought to be associated with the occurrence of a further thylakoid phosphoprotein in both lycophytes, in addition to D2, CP43 and Lhcb1‐2. This protein, which showed light intensity‐dependent reversible phosphorylation, was identified in S. martensii as Lhcb6, a minor LHCII antenna subunit of PSII. Lhcb6 is known to have evolved in the context of land colonization. In S. martensii, Lhcb6 was detected as a component of the free LHCII assemblies, but also associated with PSI. Most of the light‐induced changes affected the amount and phosphorylation of the LHCII assemblies, which possibly mediate PSI–PSII connectivity. We propose that Lhcb6 is involved in light energy management in lycophytes, participating in energy balance between PSI and PSII through a unique reversible phosphorylation, not yet observed in other land plants.
Effects of pulsed fluid lens capsule washing following phacoemulsification on lens epithelial cells and posterior capsule opacification formation ex vivo
Authors: Lutz Elizabeth A. , Gemensky‐Metzler Anne J. , Wilkie David A. , Chandler Heather L. 
Published: January 2014

AbstractBackgroundThe aim of the study was to evaluate ex vivo the effects of using a custom tip to direct a pulsed stream of fluid to remove residual lens epithelial cells (LECs) and reduce posterior capsule opacification (PCO) formation following phacoemulsification.MethodsTwenty‐four canine cadaver eyes were assigned to one of three treatment groups. Six eyes (Control Group) had standard phacoemulsification only, nine eyes (Group 1) had standard phacoemulsification followed by capsular washing using intermediate settings (power = 40%, pulses per second [PPS] = 50, 30 s washing per capsule hemisphere), and nine eyes (Group 2) had standard phacoemulsification followed by aggressive capsular washing (power = 60%, PPS = 50, 60 s washing per capsule hemisphere).ResultsControl lens capsules had diffuse LECs remaining following standard phacoemulsification and complete ex vivo PCO formation (confluent LECs on the posterior capsule) within 4 ± 2 days (range 2–8 days). Group 1 lens capsules had focal, equatorial LEC clusters remaining following treatment, and complete PCO formation within 9 ± 2 days (range 5–11 days). Group 2 lens capsules had little to no LECs observed following treatment; 5 of 9 capsules had complete PCO formation within 13 ± 2 days (range 9–14 days), and 4 of 9 capsules had no PCO formation by 24 days post‐treatment.ConclusionsPulsed fluid lens capsule washing is capable of removing LECs and delaying PCO formation in canine eyes following phacoemulsification ex vivo. Use of more aggressive capsular washing settings resulted in more effective LEC removal and subsequent delay of ex vivo PCO.
Identification of breast contour for nipple segmentation in breast magnetic resonance images
Authors: Gwo Chih‐Ying , Gwo Allen , Wei Chia‐Hung , Huang Pai Jung 
Published: January 2014

Purpose:The purpose of this study is to develop a method to simulate the breast contour and segment the nipple in breast magnetic resonance images.Methods:This study first identifies the chest wall and removes the chest part from the breast MR images. Subsequently, the cleavage and its motion artifacts are removed, distinguishing the separate breasts, where the edge points are sampled for curve fitting. Next, a region growing method is applied to find the potential nipple region. Finally, the potential nipple region above the simulated curve can be removed in order to retain the original smooth contour.Results:The simulation methods can achieve the least root mean square error (RMSE) for certain cases. The proposed YBnd and (Dmin+Dmax)/2 methods are significant due toP = 0.000. The breast contour curve detected by the two proposed methods is closer than that determined by the edge detection method. The (Dmin+Dmax)/2 method can achieve the lowest RMSE of 1.1029 on average, while the edge detection method results in the highest RMSE of 6.5655. This is only slighter better than the comparison methods, which implies that the performance of these methods depends upon the conditions of the cases themselves. Under this method, the maximal Dice coefficient is 0.881, and the centroid difference is 0.36 pixels.Conclusions:The contributions of this study are twofold. First, a method was proposed to identify and segment the nipple in breast MR images. Second, a curve‐fitting method was used to simulate the breast contour, allowing the breast to retain its original smooth shape.
Comparing deflection measurements of a magnetically steerable catheter using optical imaging and MRI
Authors: Lillaney Prasheel , Caton Curtis , Martin Alastair J. , Losey Aaron D. , Evans Leland , Saeed Maythem , Cooke Daniel L. , Wilson Mark W. , Hetts Steven W. 
Published: January 2014

Purpose:Magnetic resonance imaging (MRI) is an emerging modality for interventional radiology, giving clinicians another tool for minimally invasive image‐guided interventional procedures. Difficulties associated with endovascular catheter navigation using MRI guidance led to the development of a magnetically steerable catheter. The focus of this study was to mechanically characterize deflections of two different prototypes of the magnetically steerable catheterin vitro to better understand their efficacy.Methods:A mathematical model for deflection of the magnetically steerable catheter is formulated based on the principle that at equilibrium the mechanical and magnetic torques are equal to each other. Furthermore, two different image based methods for empirically measuring the catheter deflection angle are presented. The first, referred to as the absolute tip method, measures the angle of the line that is tangential to the catheter tip. The second, referred to the base to tip method, is an approximation that is used when it is not possible to measure the angle of the tangent line. Optical images of the catheter deflection are analyzed using the absolute tip method to quantitatively validate the predicted deflections from the mathematical model. Optical images of the catheter deflection are also analyzed using the base to tip method to quantitatively determine the differences between the absolute tip and base to tip methods. Finally, the optical images are compared to MR images using the base to tip method to determine the accuracy of measuring the catheter deflection using MR.Results:The optical catheter deflection angles measured for both catheter prototypes using the absolute tip method fit very well to the mathematical model (R2 = 0.91 and 0.86 for each prototype, respectively). It was found that the angles measured using the base to tip method were consistently smaller than those measured using the absolute tip method. The deflection angles measured using optical data did not demonstrate a significant difference from the angles measured using MR image data when compared using the base to tip method.Conclusions:This study validates the theoretical description of the magnetically steerable catheter, while also giving insight into different methods and modalities for measuring the deflection angles of the prototype catheters. These results can be used to mechanically model future iterations of the design. Quantifying the difference between the different methods for measuring catheter deflection will be important when making deflection measurements in future studies. Finally, MR images can be used to reliably measure deflection angles since there is no significant difference between the MR and optical measurements.
Silymarin Reduces Profibrogenic Cytokines and Reverses Hepatic Fibrosis in Chronic Murine Schistosomiasis
Authors: Mata-Santos Hílton Antônio , Dutra Fabianno Ferreira , Rocha Carolina Carneiro , Lino Fabiana Gonçalves , Xavier Fabiola Ramos , Chinalia Leandro Andrade , Hossy Bryan Hudson , Castelo-Branco Morgana Teixeira Lima , Teodoro Anderson Junger , Paiva Claudia N. , Pyrrho Alexandre dos Santos 
Published: January 2014

ABSTRACTIn chronic schistosomiasis, hepatic fibrosis is linked to the portal hypertension that causes morbidity inSchistosoma mansoniinfection. Silymarin (SIL) is a hepatoprotective and antioxidant medicament largely prescribed against liver diseases that has previously been shown to prevent fibrosis during acute murine schistosomiasis. Here we employed silymarin to try to reverse established hepatic fibrosis in chronic schistosomiasis. Silymarin or vehicle was administered to BALB/c mice every 48 h, starting on the 40th (80 days of treatment), 70th (50 days), or 110th (10 days) day postinfection (dpi). All mice were sacrificed and analyzed at 120 dpi. Treatment with silymarin reduced liver weight and granuloma sizes, reduced the increase in alanine aminotransferase and aspartate aminotransferase levels, and reduced the established hepatic fibrosis (assessed by hydroxyproline contents and picrosirius staining). Treatment with silymarin also reduced the levels of interleukin-13 (IL-13) in serum and increased the gamma interferon (IFN-γ)/IL-13 ratio. There was a linear correlation between IL-13 levels in serum and hydroxyproline hepatic content in both infected untreated and SIL-treated mice, with decreased IL-13 levels corresponding to decreased hydroxyproline hepatic contents. Treatment with either SIL or N-acetylcysteine reduced both proliferation of fibroblast cell lines and basal/IL-13-induced production of collagen I, indicating that besides inhibiting IL-13 production during infection, SIL antioxidant properties most likely contribute to inhibition of collagen production downstream of IL-13. These results show that silymarin interferes with fibrogenic cytokines, reduces established fibrosis, and inhibits downstream effects of IL-13 on fibrogenesis, indicating the drug as a safe and cheap treatment to liver fibrotic disease in schistosomiasis.
The Antituberculosis Antibiotic Capreomycin Inhibits Protein Synthesis by Disrupting Interaction between Ribosomal Proteins L12 and L10
Authors: Lin Yuan , Li Yan , Zhu Ningyu , Han Yanxing , Jiang Wei , Wang Yanchang , Si Shuyi , Jiang Jiandong 
Published: January 2014

ABSTRACT

Capreomycin is a second-line drug for multiple-drug-resistant tuberculosis (TB). However, with increased use in clinics, the therapeutic efficiency of capreomycin is decreasing. To better understand TB resistance to capreomycin, we have done research to identify the molecular target of capreomycin.
Mycobacterium tuberculosis
ribosomal proteins L12 and L10 interact with each other and constitute the stalk of the 50S ribosomal subunit, which recruits initiation and elongation factors during translation. Hence, the L12-L10 interaction is considered to be essential for ribosomal function and protein synthesis. Here we provide evidence showing that capreomycin inhibits the L12-L10 interaction by using an established L12-L10 interaction assay. Overexpression of L12 and/or L10 in
M. smegmatis
, a species close to
M. tuberculosis
, increases the MIC of capreomycin. Moreover, both elongation factor G-dependent GTPase activity and ribosome-mediated protein synthesis are inhibited by capreomycin. When protein synthesis was blocked with thiostrepton, however, the bactericidal activity of capreomycin was restrained. All of these results suggest that capreomycin seems to inhibit TB by interrupting the L12-L10 interaction. This finding might provide novel clues for anti-TB drug discovery.