bluuebunny/crossref_metadata_2025_split huggingface dataset:
TGFβ1 inhibits IFNγ‐mediated microglia activation and protects mDA neurons from IFNγ‐driven neurotoxicity
Authors: Zhou Xiaolai , Zöller Tanja , Krieglstein Kerstin , Spittau Björn 
Published: April 2015

AbstractMicroglia‐mediated neuroinflammation has been reported as a common feature of familial and sporadic forms of Parkinson′s disease (PD), and a growing body of evidence indicates that onset and progression of PD correlates with the extent of neuroinflammatory responses involving Interferon γ (IFNγ). Transforming growth factor β1 (TGFβ1) has been shown to be a major player in the regulation of microglia activation states and functions and, thus, might be a potential therapeutic agent by shaping microglial activation phenotypes during the course of neurodegenerative diseases such as PD. In this study, we demonstrate that TGFβ1 is able to block IFNγ‐induced microglia activation by attenuating STAT1 phosphorylation and IFNγRα expression. Moreover, we identified a set of genes involved in microglial IFNγ signaling transduction that were significantly down‐regulated upon TGFβ1 treatment, resulting in decreased sensitivity of microglia toward IFNγ stimuli. Interestingly, genes mediating negative regulation of IFNγ signaling, such as SOCS2 and SOCS6, were up‐regulated after TGFβ1 treatment. Finally, we demonstrate that TGFβ1 is capable of protecting midbrain dopaminergic (mDA) neurons from IFNγ‐driven neurotoxicity in mixed neuron‐glia cultures derived from embryonic day 14 (E14) midbrain tissue. Together, these data underline the importance of TGFβ1 as a key immunoregulatory factor for microglia by silencing IFNγ‐mediated microglia activation and, thereby, rescuing mDA neurons from IFNγ‐induced neurotoxicity.
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Interferon γ (IFNγ) is a potent pro‐inflammatory factor that triggers the activation of microglia and the subsequent release of neurotoxic factors. Transforming growth factor β1 (TGFβ1) is able to inhibit the IFNγ‐mediated activation of microglia, which is characterized by the release of nitric oxide (NO) and tumor necrosis factor α (TNFα). By decreasing the expression of IFNγ‐induced genes as well as the signaling receptor IFNγR1, TGFβ1 reduces the responsiveness of microglia towards IFNγ. In mixed neuron‐glia cultures, TGFβ1 protects midbrain dopaminergic (mDA) neurons from IFNγ‐induced neurotoxicity.
Kohn's pores are not responsible for collateral ventilation between inflated and deflated segments: a microscopic study of pulmonary intersegmental septa in the human lung
Authors: Zuo Yizhi , Li Lin , Liu Shuwei 
Published: April 2015

AbstractThe composition of the pulmonary intersegmental septum has not been clearly identified by thoracic surgeons who regard Kohn's pores as the main channel that causes air leakage when determining the intersegmental septum by segmental ventilation. In this study, we aimed to examine this possible misinterpretation by focusing on a detailed description of the microscopic anatomy of the intersegmental septum. To accomplish this aim, 50 lung samples of the intersegmental septum from fresh cadavers without emphysema were studied by histological and electron microscopy. The findings of light microscopy and electron microscopy showed that the intersegmental septum is composed of three layers. The alveolar walls of adjacent segments serve as the superficial layer. They are integral, and no Kohn's pores were identified. The deep layer contains collagen fibres. As shown by our findings, Kohn's pores are absent within the intersegmental septum. Therefore, they could not be the main channel for the collateral ventilation between inflated and deflated lung segments during a pulmonary segmentectomy.
Acoustic radiation force impulse elastography of the spleen in healthy dogs of different ages
Authors: Maronezi M. C. , Feliciano M. A. R. , Crivellenti L. Z. , Simões A. P. R. , Bartlewski P. M. , Gill I. , Canola J. C. C. , Vicente W. R. R. 
Published: April 2015

OBJECTIVESTo determine the elastographic characteristics of splenic parenchyma in clinically healthy dogs of various ages in order to establish preliminary qualitative and quantitative standards/reference intervals for this technique.MATERIALS AND METHODSThirty three healthy dogs categorized as young, adult and elderly were used. Splenic echotexture, echogenicity, size and ages were assessed with B‐mode ultrasonography. Using qualitative elastography, the spleen (head, body and tail) was examined for homogeneity and presence of deformities. Shear velocities in different splenic segments were then quantitatively evaluated.RESULTSAll splenic segments visualised with the B‐mode ultrasonography appeared normal. Different splenic segments examined with qualitative elastography were free of any detectable malformations and the images appeared as homogeneous dark areas. The mean shear velocity values were 2 · 32 m/s for head, 2 · 16 m/s for body and 2 · 25 m/s for tail of the spleen (P = 0 · 40), and they did not vary between the different age groups (P > 0 · 05).CLINICAL SIGNIFICANCEQuantitative and qualitative ARFI elastography of the spleen in clinically healthy dogs differing in age could be easily performed, and it may aid in the diagnosis and evaluation of splenic abnormalities routinely assessed in veterinary practice with B‐mode ultrasonography.
The chimerical genome of Isla del Coco feral pigs (Costa Rica), an isolated population since 1793 but with remarkable levels of diversity
Authors: Bianco E. , Soto H. W. , Vargas L. , Pérez‐Enciso M. 
Published: April 2015

AbstractThe history of domestic species and of their wild ancestors is not a simple one, and feral processes can clarify key aspects of this history, including the adaptive processes triggered by new environments. Here, we provide a comprehensive genomic study of Isla del Coco (Costa Rica) feral pigs, a unique population that was allegedly founded by two individuals and has remained isolated since 1793. Using SNP arrays and genome sequencing, we show that Cocos pigs are hybrids between Asian and European pigs, as are modern international pig breeds. This conclusively shows that, as early as the 18th century, British vessels were loading crossbred pigs in Great Britain and transporting them overseas. We find that the Y chromosome has Asian origin, which has not been reported in any international pig breed. Chinese haplotypes seem to have been transmitted independently between Cocos and other pig breeds, suggesting independent introgression events and a complex pattern of admixing. Although data are compatible with a founder population of N = 2, variability levels are as high in Cocos pigs as in international pig breeds (~1.9 SNPs/kb) and higher than in European wild boars or local breeds (~1.7 SNPs/kb). Nevertheless, we also report a 10‐Mb region with a marked decrease in variability across all samples that contains four genes (CPE, H3F3C, SC4MOL and KHL2) previously identified as highly differentiated between wild and domestic pigs. This work therefore illustrates how feral population genomic studies can help to resolve the history of domestic species and associated admixture events.
The intracellular parasite Toxoplasma gondii depends on the synthesis of long‐chain and very long‐chain unsaturated fatty acids not supplied by the host cell
Authors: Ramakrishnan Srinivasan , Docampo Melissa D. , MacRae James I. , Ralton Julie E. , Rupasinghe Thusitha , McConville Malcolm J. , Striepen Boris 
Published: April 2015

SummaryApicomplexa are parasitic protozoa that cause important human diseases including malaria, cryptosporidiosis and toxoplasmosis. The replication of these parasites within their target host cell is dependent on both salvage as well as de novo synthesis of fatty acids. In Toxoplasma gondii, fatty acid synthesis via the apicoplast‐localized FASII is essential for pathogenesis, while the role of two other fatty acid biosynthetic complexes remains unclear. Here, we demonstrate that the ER‐localized fatty acid elongation (ELO) complexes are essential for parasite growth. Conditional knockdown of the nonredundant hydroxyacyl‐CoA dehydratase and enoyl‐CoA reductase enzymes in the ELO pathway severely repressed intracellular parasite growth. 13C‐glucose and 13C‐acetate labeling and comprehensive lipidomic analyses of these mutants showed a selective defect in synthesis of unsaturated long and very long‐chain fatty acids (LCFAs and VLCFAs) and depletion of phosphatidylinositol and phosphatidylethanolamine species containing unsaturated LCFAs and VLCFAs. This requirement for ELO pathway was bypassed by supplementing the media with specific fatty acids, indicating active but inefficient import of host fatty acids. Our experiments highlight a gap between the fatty acid needs of the parasite and availability of specific fatty acids in the host cell that the parasite has to close using a dedicated synthesis and modification pathway.
Mycelial growth rate and toxin production in the seed pathogen Pyrenophora semeniperda: resource trade‐offs and temporally varying selection
Authors: Meyer S. E. , Masi M. , Clement S. , Davis T. L. , Beckstead J. 
Published: April 2015

Pyrenophora semeniperda, an important pathogen in Bromus tectorum seed banks in semi‐arid western North America, exhibits >4‐fold variation in mycelial growth rate. Host seeds exhibit seasonal changes in dormancy that affect the risk of pathogen‐caused mortality. The hypothesis tested is that contrasting seed dormancy phenotypes select for contrasting strategies for increasing pathogen fitness, and that increased fitness on nondormant seeds involves a resource trade‐off between toxin production and growth. The strategy for successfully attacking rapidly germinating nondormant seeds at high inoculum loads in autumn involves increased post‐infection aggressiveness to prevent seed escape through germination. An earlier study demonstrated that slow‐growing strains caused higher mortality than faster‐growing strains on nondormant host seeds at high inoculum loads. In this study, production of the toxin cytochalasin B was significantly higher in slower‐growing strains, and was induced only in seeds or in seed‐constituent‐containing media. Its production was reduced in vivo by Bromus tectorum seeds, suggesting direct involvement in pathogenesis on seeds. Fast‐growing strains caused significantly higher mortality than slow‐growing strains at low inoculum loads on dormant seeds, which apparently have resistance that is overcome at high loads or through rapid mycelial proliferation. In a co‐inoculation study, the fast‐growing isolate produced 3 × more stromata than the slow‐growing isolate on dormant seeds, whereas the slow‐growing isolate was twice as successful on nondormant seeds. These results provide evidence that mycelial growth rate variation and associated variation in cytochalasin B production represent a trade‐off maintained through temporally varying selection resulting from seasonal variation in host seed dormancy status.
Catheter‐directed Thrombolysis in Acute Superior Vena Cava Syndrome Caused by Central Venous Catheters
Authors: Cui Jie , Kawai Tasuo , Irani Zubin 
Published: April 2015

AbstractIndwelling central venous catheters have been reported to increase the risk of superior venous cava (SVC) syndrome. This case report describes the development of acute SVC syndrome in a 28‐year‐old woman with end‐stage renal disease implanted with a left‐side hemodialysis reliable outflow graft and a right‐side double lumen hemodialysis catheter via internal jugular veins. Her symptoms were not alleviated after catheter removal and systemic anticoagulation therapy. She was eventually treated with catheter‐directed thrombolysis and a predischarge computer tomographic venogram on postthrombolytic procedure day 7 showed patent central veins and patient remained asymptomatic. This case demonstrates that catheter‐directed thrombolysis can be safely employed to treat refractory catheter‐induced acute SVC syndrome in end‐stage renal disease patients.
Fully Bayesian Binary Markov Random Field Models: Prior Specification and Posterior Simulation
Authors: Arnesen Petter , Tjelmeland Håkon 
Published: April 2015

AbstractWe propose a flexible prior model for the parameters of binary Markov random fields (MRF), defined on rectangular lattices and with maximal cliques defined from a template maximal clique. The prior model allows higher‐order interactions to be included. We also define a reversible jump Markov chain Monte Carlo algorithm to sample from the associated posterior distribution. The number of possible parameters for a higher‐order MRF becomes high, even for small template maximal cliques. We define a flexible parametric form where the parameters have interpretation as potentials for clique configurations, and limit the effective number of parameters by assigning apriori discrete probabilities for events where groups of parameter values are equal. To cope with the computationally intractable normalising constant of MRFs, we adopt a previously defined approximation of binary MRFs. We demonstrate the flexibility of our prior formulation with simulated and real data examples.
Interactive Effects of Explicit Emergent Structure: A Major Challenge for Cognitive Computational Modeling
Authors: French Robert M. , Thomas Elizabeth 
Published: April 2015

AbstractDavid Marr's (1982) three‐level analysis of computational cognition argues for three distinct levels of cognitive information processing—namely, the computational, representational, and implementational levels. But Marr's levels are—and were meant to be—descriptive, rather than interactive and dynamic. For this reason, we suggest that, had Marr been writing today, he might well have gone even farther in his analysis, including the emergence of structure—in particular, explicit structure at the conceptual level—from lower levels, and the effect of explicit emergent structures on the level (or levels) that gave rise to them. The message is that today's cognitive scientists need not only to understand how emergent structures—in particular, explicit emergent structures at the cognitive level—develop but also to understand how they feed back on the sub‐structures from which they emerged.
Characterisation of an unusual telomere motif (TTTTTTAGGG)n in the plant Cestrum elegans (Solanaceae), a species with a large genome
Authors: Peška Vratislav , Fajkus Petr , Fojtová Miloslava , Dvořáčková Martina , Hapala Jan , Dvořáček Vojtěch , Polanská Pavla , Leitch Andrew R. , Sýkorová Eva , Fajkus Jiří 
Published: April 2015

SummaryThe characterization of unusual telomere sequence sheds light on patterns of telomere evolution, maintenance and function. Plant species from the closely related genera Cestrum, Vestia and Sessea (family Solanaceae) lack known plant telomeric sequences. Here we characterize the telomere of Cestrum elegans, work that was a challenge because of its large genome size and few chromosomes (1C 9.76 pg; n = 8). We developed an approach that combines BAL31 digestion, which digests DNA from the ends and chromosome breaks, with next‐generation sequencing (NGS), to generate data analysed in RepeatExplorer, designed for de novo repeats identification and quantification. We identify an unique repeat motif (TTTTTTAGGG)n in C. elegans, occurring in ca. 30 400 copies per haploid genome, averaging ca. 1900 copies per telomere, and synthesized by telomerase. We demonstrate that the motif is synthesized by telomerase. The occurrence of an unusual eukaryote (TTTTTTAGGG)n telomeric motif in C. elegans represents a switch in motif from the ‘typical’ angiosperm telomere (TTTAGGG)n. That switch may have happened with the divergence of Cestrum, Sessea and Vestia. The shift in motif when it arose would have had profound effects on telomere activity. Thus our finding provides a unique handle to study how telomerase and telomeres responded to genetic change, studies that will shed more light on telomere function.
Efficient Steam System Incorporates Gas Turbine Principles
Authors: Jahnig C. E. 
Published: April 2015

One approach to improving steam cycles is to apply certain gas turbine technology, namely, direct combustion to achieve a high working temperature. Direct combustion supplies heat and also working fluid, without the need for high temperature heat exchange. By burning hydrogen with pure oxygen the only product of combustion is steam; consequently, no inert gas is introduced into the system. In a similar manner direct combustion is used to maintain temperature during the first part of the expansion so as to approach an isothermal expansion rather than the adiabatic expansion typical of steam systems.
Such a modified steam cycle is described in this paper and shows a projected fuel efficiency of 58% when the maximum temperature is 1093 C., or 50% for 815 C. maximum. Practical ways to supply hydrogen and oxygen are discussed.
Power Dense Gas Turbine APUs
Authors: Rodgers Colin 
Published: April 2015

Future high performance aircraft will require more compact, lighter weight, and self-sufficient secondary power equipment capable of faster starting and delivering high specific powers over wider operating envelopes of inlet temperatures and altitudes.
Meeting these requirements may not be entirely compatible with improving thermal efficiency, particularly for the small air-breathing gas turbine since optimum cycle conditions differ for maximum specific power and specific fuel consumption. Further conflict lies in the necessity to provide faster start times with a limited capacity of stored on-board start energy, because compressor and turbine inertias must be minimized although compressor and turbine airflow-swallowing capacity must be maximized.
This paper discusses the numerous design disciplines which constrain power density for small gas turbine auxiliary power units. Several potentially profitable development avenues are suggested for continuing the improvement of aircraft system performance.
Industrial Silencers for Gas Turbine Power Plants
Authors: Weirich Paul T. , Capek Zdenek A. 
Published: April 2015

In gas turbine power plants, the major sources of noise are turbine inlet and exhaust. The following aspects of gas turbine silencers are discussed:
A. Criteria for turbine inlet and exhaust silencers — Design requirements and materials to meet noise criteria and to increase life expectancy of silencers.
B. Description of exhaust silencer system — Consisting of expansion seal, transition, exhaust silencer and other equipment.
C. Field measurement of exhaust silencer system — Description of turbine unit, noise sources, location of measuring points, measured noise data, and discussion of results.
60% Efficient Gas Turbine System for Base Load Use
Authors: Jahnig C. E. 
Published: April 2015

Efforts to improve the performance of combustion gas turbines has emphasized increasing the operating temperature. This paper shows that an alternative approach using higher pressure is very attractive, giving efficiencies of 55–60% together with much more power output at a given air flow. Maximum temperature is 1200 C. at a pressure of 300 atmospheres.
The new systems use supplemental combustion within the gas turbine to approach an isothermal expansion, in contrast to the adiabatic expansion normally used with gas turbines. Details for three specific systems are compared in the paper.
Gas Turbine Combustion of a Minimally Cleaned, Coal-Derived Low-BTU Gas
Authors: Blanton John C. , Smith Daniel P. 
Published: April 2015

As part of the joint GE/DoE Water-Cooled Components Test Program,1 a series of tests were performed involving the combustion of a minimally cleaned low-Btu coal gas in a pressurized gas turbine simulator. The fuel gas was produced in a 1-ton/hr advanced fixed-bed gasifier using Illinois #6 coal, and filtered of particulate in a full-pressure, full-temperature cyclone separator. The resulting product had a gross heating value of approximately 5000 kJ/kg at a temperature of 540 °C and a pressure of 22 bar. Numerous contaminants also remained in the fuel gas, including approximately 100 ppmw particulate matter (coal dust of 3 μm average size), 2000–4000 ppmv ammonia, 2000–2500 ppmv H2S, and 0.5–1.0% vaporized tars, oils, phenols, and other condensible hydrocarbons.
The fuel gas was burned with air at 6–7 bar pressure and 400 °C temperature in a gas turbine combustion system at overall fuel-air ratios up to 0.25 (overall equivalence ratio 0.36). Gaseous emissions were sampled in the exhaust stream and measurements made for O2, CO2, CO, unburned hydrocarbons, NOx, and SOx. The CO and unburned hydrocarbon emissions were both below 20 ppmv at full firing conditions, indicating acceptable combustion efficiency. The NOx levels measured were up to 500 ppmv, and were due to the of conversion of fuel-bound nitrogen (ammonia principally). The SOx emissions directly followed the oxidation of fuel-bound sulfur (H2S principally). At part-load conditions, emissions of CO and unburned hydrocarbons were observed to increase, as expected. Stable operation was maintained down to a combustion system temperature rise of approximately 350 °C.
Thermal Preconditioning of Coal/Water Mixtures for Gas Turbine Applications
Authors: Roffe Gerald , Miller Gabriel 
Published: April 2015

Thermal preconditioning of coal/water mixtures (CWM) is a process proposed for use with stationary gas turbine engines. The CWM is heated before delivery to the combustor to vaporize the water and to pyrolyze and devolatilize the coal prior to injection. The process offers a number of potential advantages. Engines can be started without the use of an auxiliary fuel system, atomizing nozzles are eliminated, flame stability is increased, and char burnout is accelerated as a result of increased initial flame intensity.
This project was an initial examination of technical questions affecting the feasibility and utility of the process. Heat transfer rates were measured for high solids loadings CWM in tubular heaters, the influence of the boiling process was studied, devolatilization rates were measured for the conditions of interest in gas turbine applications, the potential for organic sulfur volatilization was assessed and the effect of the process on heat rate for a combined cycle power plant was examined. The results of this initial examination showed the process to be both technically and economically feasible. CWM was vaporized and devolatilized in a small heat exchanger and a clearly defined steam/char/volatile suspension was produced. Temperatures of 750K to 870K and residence times of less than 1 second were found to be adequate to complete the process.
Experimental Investigation on Spatial Development of Streamwise Vortices in a Turbine Inlet Guide Vane Cascade
Authors: Sonoda Toyotaka 
Published: April 2015

In order to obtain a better understanding of secondary flow in a turbine cascade, spatial development of a leading-edge horseshoe vortex has been investigated experimentally in a large-scale, low-speed, high-accelerated, plane turbine inlet guide vane cascade. Flow has been visualized by issuing kerosene vapor into the inlet boundary layer and the vane suction surface boundary layer, respectively.
Based on many cross-sectional photographs normal to the flow and supplemental measurements of the wall static pressure on the vane and the endwall, the evolution of a leading-edge horseshoe vortex into streamwise vortices and the generation of a new type streamwise vortex pair on the suction surface near the endwall are discussed.