bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is serum amyloid A an endogenous TLR4 agonist?
Authors: Sandri Silvana , Rodriguez Dunia , Gomes Eliane , Monteiro Hugo Pequeno , Russo Momtchilo , Campa Ana 
Published: February 2008

AbstractSerum amyloid A (SAA), a classical acute-phase protein, is produced predominantly by hepatocytes in response to injury, infection, and inflammation. It has been shown that SAA primes leukocytes and induces the expression and release of proinflammatory cytokines. Here, we report that SAA induces NO production by murine peritoneal macrophages. Using specific inhibitors, we showed that NO production was dependent on inducible NO synthase thorough the activation of ERK1/2 and p38 MAPKs. Moreover, SAA activity was decreased after proteolysis but not with polymyxin B, a lipid A antagonist. Finally, we found that NO production was dependent on functional TLR4, a receptor complex associated with innate immunity. Macrophages from C3H/HeJ and C57BL/10ScCr mice lacking a functional TLR4 did not respond to SAA stimulation. In conclusion, our study makes a novel observation that SAA might be an endogenous agonist for the TLR4 complex on macrophages. The contribution of this finding in amplifying innate immunity during the inflammatory process is discussed.
LPS-induced up-regulation of TGF-β receptor 1 is associated with TNF-α expression in human monocyte-derived macrophages
Authors: Chen Yan , Kam Christy S K , Liu Feng Qin , Liu Yan , Lui Vincent C H , Lamb Jonathan R , Tam Paul K H 
Published: February 2008

AbstractThe immunosuppressive activity of TGF-β-mediated signaling is well documented, but in contrast, its ability to promote proinflammatory responses is less clear. In this study, we report that blockade of TGF-β signaling by a specific inhibitor of the TGF-β receptor I [activin receptor-like kinase 5 (ALK5)] SB431542 significantly reduces the production of TNF-α, a key proinflammatory cytokine, by LPS-stimulated human monocyte-derived macrophages. ALK5 protein was only detectable after LPS stimulation, and the failure of treatment with SB431542 to alter TNF-α mRNA expression indicates that regulation is post-transcriptional. The additive effect of blocking TGF-β and p38 MAPK signaling on reducing TNF-α but not IL-6 production suggests that there is selectivity in pathway signaling. SB431542 had similar inhibitory effects on TNF-α production by human monocytes and endothelial cells as well as macrophages. Furthermore, treatment with SB431542 reduced plasma TNF-α levels and tissue damage and thereby, prevented the lethal effects of LPS in a mouse model of septic shock. Our data demonstrate a direct effect of TGF-β signaling via ALK5 on the regulation of TNF-α synthesis.
Conducting ferromagnetic copolymer of aniline and 3,4‐ethylenedioxythiophene containing nanocrystalline barium ferrite particles
Authors: Ohlan Anil , Singh Kuldeep , Chandra A. , Dhawan S. K. 
Published: February 2008

AbstractThis article reports the synthesis of conducting ferromagnetic complex of 3,4‐ethylenedioxythiophene (EDOT) and aniline (An) containing M‐type hexagonal barium ferrite (BaFe12O19) particles using in situ emulsion polymerization and electrochemical oxidative polymerization. Magnetic and conductivity studies reveal that the conducting ferromagnetic complex possesses high‐saturation magnetization (Ms) value of 29.2 emu/g and conductivity of the order of 0.256 S/cm determined through vibrating sample magnetometer and four‐probe method. Microwave measurement has shown the reflection loss (RL) of −12.1 dB in Ku‐band that can be used as a microwave absorbing material. The polymer complex was further characterized by techniques like X‐ray diffraction, Fourier transform infrared, UV–visible, cyclic voltammetry, and thermal analysis with thermogravimetric analysis. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Amphiphilic Cyclodextrins – Advances in Synthesis and Supramolecular Chemistry (Eur. J. Org. Chem. 6/2008)
Authors: Sallas Florence , Darcy Raphael 
Published: February 2008

AbstractThe cover picture shows a simulated micelle formed by amphiphilic cyclodextrin molecules above a landscape of real cyclodextrin vesicles. Synthesis of amphiphilic cyclodextrins, and the ranges of supramolecular assemblies formed by them, are presented in the Microreview by F. Sallas and R. Darcy on p. 957 ff.
Challenges for alexithymia research: a commentary on “The construct of alexithymia: associations with defense mechanisms”
Authors: Vanheule Stijn 
Published: February 2008

AbstractThe author comments on an article by Helmes and colleagues (this issue, pp. 000–000) that studied defense mechanisms related to alexithymia. What these authors observed is theoretically meaningful, and a distinct strength of this study is that the results are replicated in three independent samples. The study is also exemplary for two typical drawbacks— only student samples and self‐report measures are used. The author suggests that when studying alexithymia, researchers use samples that contain a substantial number of alexithymic subjects. Furthermore, variables such as emotional processing and regulation should not be measured with self‐report questionnaires alone. Emotional processing and regulation are, in part, implicit and researchers should consider this. The author argues that the standard of alexithymia research could be raised by including interdisciplinary perspectives and experimental methods, and by embedding research more explicitly in theories. © 2008 Wiley Periodicals, Inc. J Clin Psychol 64: 1–6, 2008.
Benchmarking urban six‐degree‐of‐freedom simultaneous localization and mapping
Authors: Wulf Oliver , Nüchter Andreas , Hertzberg Joachim , Wagner Bernardo 
Published: February 2008

AbstractQuite a number of approaches for solving the simultaneous localization and mapping (SLAM) problem exist by now. Some of them have recently been extended to mapping environments with six‐degree‐of‐freedom poses, yielding 6D SLAM approaches. To demonstrate the capabilities of the respective algorithms, it is common practice to present generated maps and successful loop closings in large outdoor environments. Unfortunately, it is nontrivial to compare different 6D SLAM approaches objectively, because ground truth data about the outdoor environments used for demonstration are typically unavailable. We present a novel benchmarking method for generating the ground truth data based on reference maps. The method is then demonstrated by comparing the absolute performance of some previously existing 6D SLAM algorithms that build a large urban outdoor map. © 2008 Wiley Periodicals, Inc.
Change of surface property of dental impression materials according to time and disinfection
Authors: Kim Soo‐Hwa , Lee Doug‐Youn , Kim Kwang‐Mahn , Kim Kyoung‐Nam 
Published: February 2008

AbstractThe purpose of this study was to investigate the hydrophilicity of dental impression materials. Two ultrahydrophilic (Fusion, Genie) and four hydrophilic (Imprint II, Aquasilultra, Twinz, Perfect‐F) impression materials were used. Initially, 0.5% NaOCl and 1% povidone were used as disinfectants. In order to investigate the change of the surface wettability of impression materials according to the elapsed time after mixing, the contact angles were measured at 30 s and 2 min after mixing, respectively. Contact angles were also measured before and after disinfection. The contact angles of the ultrahydrophilic impression materials were lower at 2 min than at 30 s, whereas those of the hydrophilic impression materials showed the opposite result (p < 0.05). Fusion and Perfect‐F had higher contact angles in the NaOCl‐group and lower contact angles in the povidone‐group than those of nondisinfection group (p < 0.05). The contact angles of Aquasilultra and Twinz in the povidone‐group were higher than those in the nondisinfection group (p < 0.05). The elapsed time after mixing and disinfection of impression materials affected the contact angle of water on the surface of the impression materials. These results suggested that impression materials should only be used within the scope that their wettability is not degraded. Copyright © 2008 John Wiley & Sons, Ltd.
Correlations between ion conics and electron beams observed by the Viking satellite in the cusp‐cleft region
Authors: Thelin B. , Lundin R. , Aparicio B. 
Published: February 2008

Measurements of upward electron beams and ion conics from the polar orbiting Viking satellite have been obtained in the cusp‐cleft region. The relative frequencies of occurrence have been calculated for studies of the MLT, Inv. Lat, and altitude distribution during the period March to June 1986. It was observed that the upward electron beams were more frequent in the dawn sector compared to the dusk sector. Similar observations have also been seen for ion conics.The Invariant Latitude dependence of upflowing electron beams shows a clear maximum around 78°. This agrees well with the maximum for ion conics.The altitude dependence shows a steep increase in frequency above 10,000 km up to the satellite apogee (≈ 13 500 km). This altitude dependence at different AE index was also studied giving information about the acceleration region and the altitude profiles at different levels of magnetic disturbance.
Mesospheric oh airglow temperature fluctuations: A spectral analysis
Authors: Dewan E. M. , Pendleton W. , Grossbard N. , Espy P. 
Published: February 2008

A field campaign under Project MAPSTAR was conducted in Colorado during May‐July 1988. As part of this effort ground based measurements of OH airglow rotational temperatures at 85 km were made by means of an infrared Fourier spectrometer (IRFWI of USU). These measurements employed a least squares spectral fitting technique involving the 3–1 Meinel band. These data and their estimated PSD's will be presented. The latter will be interpreted by means of the relations between gravity wave temperature fluctuations and vertical displacement fluctuations given by Makhlouf et al (1990).The results will be compared with the predictions of the gravity wave model of Dewan (1990, 1991) and shown to be in reasonable agreement thus lending further support to the local wave‐cascade hypothesis.
Triassic paleomagnetic results from the Yangtze Block, S.E. China
Authors: Dobson Jon Paul , Heller Friedrich 
Published: February 2008

In an effort to contribute to the refinement of the APWP for the Yangtze Block, samples for paleomagnetic analyses were recovered from early Triassic sediments in Hunan Province in southeast China. The samples were taken from opposite limbs of a large syncline in order to apply the fold test and rock magnetic experiments were performed to determine the carriers of remanence. However, instead of refining the APWP, the results present some problems.While the sites pass the fold test, the declinations deviate clockwise with respect to the reference APWP for the block but agree well with other reported results. Due to the paucity of reliable Triassic results from the Yangtze Block and to the small number of sites from this study, it is difficult to determine whether these sites have been rotated or the APWP is incorrect. Both possibilities are explored.
Enormous increase of stratospheric aerosols over Fukuoka due to volcanic eruption of El Chichon in 1982
Authors: Hirono M. , Shibata T. 
Published: February 2008

Large increases of stratospheric aerosol particles caused by the eruption of Mexican volcano El Chichon in early April 1982 were observed by a Yag lidar system at two wavelengths (1.06 µm and 0.53 µm) over Fukuoka for three months since April 18. Most of the observations show high concentrations of aerosols in the altitude regions from 15 to 33 km, with highest concentrations between 21 and 30 km. The aerosol optical thickness at 0.55 µm is about 0.1 ‐ 0.3; this is about 10 to 30 times the maximum monthly mean values that were observed after the Mt. St. Helens event in 1980.The mean radius of aerosols in the densest part of the El Chichon cloud is estimated to be approximately 0.1 µm. This estimate is based on the slow settling velocity of the peak of the cloud and from information obtained by comparison of the two‐wavelength lidar returns.A significant impact of the presence of the cloud on the climate through variations of atmospheric circulation is suggested.
Concentrations and radiocarbon signatures of dissolved organic matter in the Pacific Ocean
Authors: Druffel Ellen R. M. , Williams Peter M. , Suzuki Yoshimi 
Published: February 2008

We present evidence suggesting that only a portion of the dissolved organic carbon (DOC) in the seawater analyzed previously by Williams and Druffel (1987) was oxidized by the UV‐radiation method. High temperature catalytic (HTC) methods (Sugimura and Suzuki, 1988) used to reoxidize the central North Pacific gyre water samples reveal that the total DOC (DOCHTC) is about twice that of the UV‐oxidizable DOC (DOCuv). Indications from the original study suggest that this additional DOC contains higher concentrations of radiocarbon than in the DOCuv(Williams and Druffel, 1987). This evidence implies that DOC is older and thus more refractory with respect to biological utilization, yet is more chemically reactive with respect to photooxidation, than the fraction resistant to UV (DOCres).We report accelerator mass spectrometry (AMS) Δ14C measurements of humic, fulvic and hydrophilic acid fractions isolated from water collected at 180 m in the North Pacific (19°N, 158°W) using XAD macroreticular resins. Δ14C values of the humic material are less than those of DOCuv from a similar depth 1200 km further north (Williams and Druffel, 1987) indicating that these humic substances are part of the ‘old’ recycled DOCuv in the ocean.
Rapid whistler‐mode wave growth resulting from frequency‐time curvature
Authors: Helliwell R. A. , Mielke T. , Inan U. S. 
Published: February 2008

The rapid (<50 ms) temporal growth of ducted whistlers is simulated using controlled injection of VLF pulses from the Siple Station, Antarctica transmitter. The results show that, when the frequency‐time function of the injected pulse has a positive slope and negative curvature, producing a kind of “chirp” such that it approximates the f(t) shape of a lightning‐generated whistler at frequencies above the ‘nose’ frequency, growth up to a saturation level (20–30 dB) commonly occurs within <50 ms as opposed to 200–300 ms that is required for monochromatic input signals. The phenomenon is explained in terms of second‐order‐resonance theory [Helliwell, 1967; Carlson et al., 1985; Chang et al., 1983] where the frequency variation of the pulse matches the changing cold plasma parameters, facilitating enhanced resonance interactions over extended portions of the field line.Magnetospheric whistler‐mode signals that originate in ground sources (e.g. lightning, VLF transmitters) often stimulate or trigger nonlinear responses in the form of amplified signals, narrowband variable frequency emissions and complex sidebands [Helliwell, 1988]. One such effect commonly associated with nose whistlers is the growth of the whistler in the upper part (above the ‘nose’) of its frequency range and the associated emission triggering that tends to occur at the whistler's upper cutoff frequency (usually at 0.5 fH, where fH is the equatorial electron gyrofrequency). An example of the dynamic spectrum of such an event is shown in Figure 1a where the growth of the whistler is represented by the darkening and broadening of the upper segment of the trace. The whistler triggered emission is, in essence, a narrowband oscillation of slowly‐varying center frequency. What makes this phenomenon remarkable is the relatively short time (∼50 ms) of growth (∼20dB) of the whistler compared with the time (200–400 ms) required for a monochromatic signal under comparable conditions to exhibit the same growth [Helliwell, 1988]. Since the triggered emissions associated with whistlers and constant frequency signals (such as those from VLF transmitters) are comparable in their intensities (as observed on the ground or on satellites) and spectral characteristics, one might expect the mechanisms of their generation to be the same. On the other hand, since the typical peak intensities of whistlers excited by lightning impulses are likely to exceed the signal level injected from ground‐based transmitters that have been used in such experiments, one might simply attribute the observed difference in behavior to unknown nonlinear effects (none is suggested here) related to the high intensity of the input signals. In this paper, we describe a new experiment where the upper part (i.e. frequencies above the nose frequency [Helliwell, 1965]) of a one‐hop nose whistler is simulated using the Siple Station experimental VLF transmitter [Helliwell, 1988] to reproduce two‐hop nose whistlers that may exhibit the rapid growth described above (e.g. Figure 1a).
Simultaneous HF‐radar and DMSP observations of the cusp
Authors: Baker K. B. , Greenwald R. A. , Ruohoniemi J. M. , Dudeney J. R. , Pinnock M. , Newell P. T. , Greenspan M. E. , Meng C.‐I. 
Published: February 2008

The Geospace Environment Modeling (GEM) Program is directed toward modeling the coupled solar wind/magnetosphere/ionosphere system. The inter‐calibration of ground‐based observations of the ionosphere and satellite observations has been identified as an essential step in tying together the data to produce a global picture of geospace.On October 10,1988 the DMSP‐F9 satellite passed through the southern hemisphere cusp while a coherent scatter HF‐radar was observing 10‐m scale irregularities present in the ionosphere. The combined data indicate that these irregularities were being generated in the cusp, and that the cusp was a region of greater than normal electric field turbulence. The radar data indicate that the cusp was co‐located with the region where the ionospheric convection rotated from sunward to anti‐sunward with increasing latitude. These observations provide an unambiguous case where simultaneous satellite and ground‐based observations of the cusp can be compared.
What causes the warp in the heliospheric current sheet?
Authors: Wilcox John M. , Scherrer Philip H. 
Published: February 2008

Thomas and Smith [1980] give an excellent description of the observations of the interplanetary magnetic field by the spacecraft Pioneer 10 and 11. Our purpose in this note is to discuss one aspect of their interpretation of their observations.They suggest that the fast solar wind streams associated with interaction regions may move the current sheet to higher heliographic latitudes. We have recently shown [Wilcox et al., 1980] that observations of the interplanetary magnetic field polarity in early 1976 obtained at several locations in the heliosphere at Helios 1, Helios 2, and earth show a rather detailed agreement with a warped heliospheric current sheet calculated from the observed photospheric magnetic field using a potential field method. It appears that at least in early 1976 the observations of the warped heliospheric current sheet are adequately explained using the observed photospheric magnetic field, and it is therefore not necessary to postulate that fast streams associated with interaction regions may move the current sheet to higher heliographic latitudes.
Separation of magnetic components from af step demagnetization data by least squares computer methods
Authors: Stupavsky M. , Symons D. T. A. 
Published: February 2008

A least squares mathematical modeling technique is used to analyze af step demagnetization data of an individual rock specimen. Its total magnetization is separated to give the directions, magnitudes, and decay rates of the inherent magnetization components. An estimate of the uncertainty in the directions and magnitudes of the components is also computed. The method assumes that the direction of each component remains constant as its intensity decreases approximately exponentially during demagnetization. Two tests comparing the mean directions determined by using the af demagnetization data of a single specimen per site to those determined by using traditional paleomagnetic analysis of multiple demagnetized specimens per site given identical results at the 95% confidence level.The computer program used in this study, with explanatorycomment, is available with entire article on microfiche. Order fromAmerican Geophysical Union, 1909 K Street, N. W., Washington, D. C.20006. Document J78‐005; $1.00. Payment must accompany order.
Velocity structure of the Pamir‐Hindu Kush Region: Possible evidence of subducted crust
Authors: Roecker S. W. 
Published: February 2008

The arrival times of compressional (P) and shear (S) waves from approximately 580 microearthquakes recorded by a temporary array in the Pamir‐Hindu Kush region in central Asia are used to deduce one‐ and three‐dimensional velocity structures of this region. The results for one‐dimensional structures imply that the Moho is at 70±5 depth. Also, there is a velocity reversal near 160 km depth, which is inferred to be the beginning of the low velocity zone. This reversal continues to depths of approximately 230 km. Below 230 km, velocities are somewhat higher than those of normal mantle at similar depths (9.3 km/s versus 8.4 km/s for P waves). The outstanding feature of the results for three‐dimensional velocity structures is a broad (>40 km), centrally located region with 8 to 10% lower velocities than those in the surrounding regions. This low velocity region envelopes the seismic zone at depths between 70 and 150 km. The region may actually extend beyond these depths, but the results for shallower and deeper structure lack sufficient resolution to decide. Several tests, using both hypothetical and real data, were performed to estimate the reliability of the three‐dimensional solutions. The results of these tests suggest that the inferred velocities are reasonably accurate representations of the average velocities in the blocks, although one must be cautious of the effects of averaging in interpreting the solution. The low velocity region is inferred to be a manifestation of substantial quantities of subducted continental crust. Therefore, while subduction has occurred in the Pamir‐Hindu Kush, the results of the three‐dimensional inversions suggest that continental rather than only oceanic lithosphere has been subducted to depths of at least 150 km.Appendices are available with the entire article on microfiche. Order from American Geophysical Union, 2000 Florida Avenue, N.W., Washington, D.C., 20009. Document J81‐013; $1.00. Payment must accompany order.
Eruption age of a Pleistocene basalt from 40Ar−39Ar analysis of partially degassed xenoliths
Authors: Glllespie A. R. , Huneke J. C. , Wasserburg G. J. 
Published: February 2008

The appendixes are available with the entire article on microfiche. Order from American Geophysical Union, 2000 Florida Avenue, N.W.,Washington, D.C. 20009. Document B83‐003; $2.50. Payment must accompany order.We have applied 40Ar−39Ar dating to potassium‐rich granitic xenoliths and host basalt from the Pleistocene Big Pine volcanic field, California. These xenoliths had been partially degassed upon their inclusion in the basaltic lava. Argon released from the xenoliths at extraction temperatures below ∼900°C yielded plateau ages indistinguishable from the total K‐Ar age of the basalt. The best estimate of the age of eruption was 1.18±0.05 (2σ) m.y. 40Ar extracted at higher temperatures included radiogenic argon not degassed from the late Cretaceous xenoliths 1.18 m.y. ago, causing an increase in the apparent age for the high‐temperature fractions. The agreement of the low‐temperature xenolith plateau ages and the basalt K‐Ar ages demonstrates that 40Ar−39Ar analysis of xenoliths may be used to measure the age of eruption of very young lavas. This is significant because in many instances ages cannot be reliably determined by analysis of the lavas themselves.