bluuebunny/crossref_metadata_2025 huggingface dataset:
Antigen-Specific Cellular and Humoral Responses Are Induced by Intradermal
Mycobacterium leprae
Infection of the Mouse Ear
Authors: Duthie Malcolm S. , Reece Stephen T. , Lahiri Ramanuj , Goto Wakako , Raman Vanitha S. , Kaplan Juliette , Ireton Greg C. , Bertholet Sylvie , Gillis Thomas P. , Krahenbuhl James L. , Reed Steven G.
Published: August 2007

Leprosy is caused by infection with
Mycobacterium leprae
. The immune response of leprosy patients can be highly diverse, ranging from strong cellular responses accompanied by an apparent deficit of
M. leprae
-specific antibodies to strong humoral responses with a deficit of cell-mediated responses. Leprosy takes many years to manifest, and this has precluded analyses of disease and immune response development in infected humans. In an attempt to better define development of the immune response during leprosy we have developed an
M. leprae
ear infection model. Intradermal inoculation of
M. leprae
into the ear supported not only infection but also the development of a chronic inflammatory response. The inflammatory response was localized, comprising a T-cell infiltration into the ear and congestion of cells in the draining lymph nodes. The development of local chronic inflammation was prevented by rifampin treatment. Importantly, and in contrast to subcutaneous
M. leprae
footpad infection, systemic
M. leprae
-specific gamma interferon and antibody responses were detected following intradermal ear infection. These results indicate the utility of intradermal ear infection for both induction and understanding of the immune response during
M. leprae
infection and the identification or testing of new leprosy treatments.
Helicobacter pyloriInduces CCL20 Expression
Authors: Tomimori Koh , Uema Eriko , Teruya Hiromitsu , Ishikawa Chie , Okudaira Taeko , Senba Masachika , Yamamoto Kazuo , Matsuyama Toshifumi , Kinjo Fukunori , Fujita Jiro , Mori Naoki
Published: August 2007

CCL20 attracts immature dendritic cells and memory T cells and plays a role on mucosal surfaces in inflammation. However, whetherHelicobacter pyloriinfection induces CCL20 in human gastric epithelial cells remains to be determined. The aim of this study was to analyze the molecular mechanism ofH. pylori-induced CCL20 expression. Expression of CCL20 mRNA was assessed by reverse transcription-PCR. Five normal and fiveH. pylori-infected gastric tissue samples were stained immunohistochemically for CCL20. A luciferase assay was used to monitor activation of the CCL20 gene promoter, and an electrophoretic mobility shift assay was used to explore the binding of transcription factors to this promoter. The CCL20 expression in epithelial cells ofH. pylori-positive tissues was higher than that inH. pylori-negative tissues.H. pyloriinduced CCL20 expression in gastric epithelial cell lines, and the induction was dependent on an intactcagpathogenicity island. Activation of the CCL20 promoter byH. pylorioccurred through the action of NF-κB. Transfection of IκB kinase and NF-κB-inducing kinase dominant negative mutants inhibitedH. pylori-mediated activation of CCL20. Treatment with an inhibitor of Hsp90 suppressedH. pylori-induced CCL20 mRNA due to deactivation of NF-κB. Collectively, these results suggest thatH. pyloriactivates NF-κB through an intracellular signaling pathway that involves IκB kinase and NF-κB-inducing kinase, leading to CCL20 gene transcription, and that Hsp90 is a crucial regulator ofH. pylori-induced CCL20 expression, presumably contributing to the immune response inH. pylori.
EFFECTS OF A BOUNDARY ON SPONTANEOUS EXCITATION OF AN ACCELERATED MULTILEVEL ATOM COUPLED WITH THE DERIVATIVE OF SCALAR FIELDS
Authors: ZHU YUNFENG , YU HONGWEI
Published: August 2007

The presence of boundaries modifies the modes of quantum fields, which may in turn modifies the spontaneous excitation rate of accelerated atoms in interaction with these fields. In this paper, we study the effect of the presence of a reflecting boundary on the spontaneous excitation of a uniformly accelerated polarized multilevel atom interacting with quantum scalar fields in a dipole-derivative coupling scheme. We separately calculate the contributions of modified vacuum fluctuations and the radiation reaction to the spontaneous excitation rate of the atom. Our results show that the presence of the boundary modulates the excitation rate and makes it a function of the atom's distance from the boundary. When the atom is placed closer and closer to the boundary, the influence of the boundary becomes more and more drastic, with the contribution of the atom's polarization in the direction parallel to the boundary to the spontaneous excitation rate dramatically suppressed while that in the normal direction greatly enhanced.
LIMITS ON THE ELECTROMAGNETIC AND WEAK DIPOLE MOMENTS OF THE TAU-LEPTON IN E6 SUPERSTRING MODELS
Authors: GUTIÉRREZ-RODRÍGUEZ A. , HERNÁNDEZ-RUÍZ M. A. , PÉREZ M. A.
Published: August 2007

We obtain limits on the electromagnetic and weak dipole moments of the tau-lepton in the framework of a left–right symmetric model (LRSM) and a class of E6 inspired models with an additional neutral vector boson Zθ. Using as an input the data obtained by the L3 and OPAL collaborations for the reaction e+e- → τ+τ-γ, we get a stringent limit on the LRSM mixing angle ϕ, -1.66 × 10-3 < ϕ<1.22×10-3, which in turn induces bounds on the tau weak dipole moments which are consistent with the bounds obtained recently by the DELPHI and ALEPH collaborations from the reaction e+e-→τ+τ-. We also get similar bounds for the weak dipole moments of the tau lepton in the framework of E6 superstring models.
TIME AND M-THEORY
Authors: JEJJALA VISHNU , KAVIC MICHAEL , MINIC DJORDJE
Published: August 2007

We review our recent proposal for a background-independent formulation of a holographic theory of quantum gravity. The present paper incorporates the necessary background material on geometry of canonical quantum theory, holography and space–time thermodynamics, Matrix theory, as well as our specific proposal for a dynamical theory of geometric quantum mechanics, as applied to Matrix theory. At the heart of this review is a new analysis of the conceptual problem of time and the closely related and phenomenologically relevant problem of vacuum energy in quantum gravity. We also present a discussion of some observational implications of this new viewpoint on the problem of vacuum energy.
ON THE MODIFIED KKLT PROCEDURE: A CASE STUDY FOR THE P11169[18] MODEL
Authors: CURIO GOTTFRIED , SPILLNER VERA
Published: August 2007

We probe the existence of supersymmetric vacua of the type IIB orientifold of the elliptic Calabi–Yau space P11169[18] where generically two complex structure moduli zi, the dilaton τ and the two Kähler moduli Ti are stabilized by fluxes and gaugino condensates. The usual KKLT procedure, which integrates out the complex structure moduli and the dilaton, actually has to be modified, such that one keeps the dependence on τ. We derive explicitly the resulting effective superpotential W eff (τ) for the dilaton for various flux combinations. As this is actually a nonholomorphic quantity one must properly work with the G-function. The remaining SUSY equations for τ and the Ti can be resolved explicitly.
Nickel Electrodeposition under Magnetic Field
Authors: Motoyama Munekazu , Fukunaka Yasuhiro , Sakka Tetsuo , Ogata Yukio , Kikuchi Shiomi
Published: August 2007

Nickel was electrodeposited on a vertical silver cathode immersed in aqueous electrolyte solutions with various pH values under an external magnetic field of 0.5 T. The current density decreased, while the current efficiency slightly increased in a 0.5 T field, especially in the negative electrode potential region at pH 3.4 and 5.5. Surface morphology of Ni films in a 0.5 T field is hardly different from that without magnetic field. Crystal preferred orientation of Ni films varied with the pH as well as electrode potential. The electrode potential at which the preferred orientation transition from {100} to {110} appeared was shifted in the negative direction at pH 3.4 and 5.5 under a 0.5 T field. Ni films showed the dominant {110} preferred orientation in the high overpotential region regardless of the pH.
The Long Journey in Perpendicular Magnetic Recording -From the Beginning to the Future
Authors: Nakamura Yoshihisa
Published: August 2007

Perpendicular magnetic recording finally became commercialized as hard disk drives about 30 years after the authors began their research into perpendicular magnetic recording. In this paper, their past and present works are introduced for future development of perpendicular magnetic recording. Through this paper, the author offers a basic philosophy retained during the long journey of the research and development in perpendicular magnetic recording.
Electrodeposition of FeCoRu Alloy
Authors: Huang Qiang , Bonhote Christian , Lam J. , Romankiw Lubomyr T.
Published: August 2007

The electrodeposition of FeCoRu alloys was studied with rotating disk electrode, surface pH measurements and galvanotstatic plating in a paddle cell. The Ru deposition does not occur until a potential of -0.9 V versus MSE is reached, much higher than the literature reversible potential. In the FeCoRu system, the presence of Ru inhibits the Fe plating rate but exerts no effect on the Co. Surface pH measurements further confirmed the high potential for Ru deposition and a significant hydrogen evolution reaction was observed causing enhanced local agitation at the electrode surface. The effect of complexing agent was also studied for FeCoRu plating. The presence of citrate, tartrate or histidine, were all found to decrease the current efficiency at the conditions of study. While the decrease observed in the citrate and tartrate cases was probably due to the buffering effect, which increases the hydrogen evolution current, histidine was believed to complex with metal cations and to inhibit the metal deposition.
Electroless Deposition of Ultra-Thin Co-Fe Films
Authors: Franz Silvia , Borioli Carlo , Bestetti Massimiliano , Cantoni Matteo , Cavallotti Pietro Luigi L.
Published: August 2007

The deposition kinetics and the magnetic properties of Cox-Fe1- x (30<x<40) soft magnetic films (< 10000 Aå) obtained by electroless deposition were investigated. In particular, the effect of film thickness on easy-axis coercivity was studied. Three organic additives were used: sodium saccharin, saccharin and maltose. In the initial stages of the deposition process, maltose greatly inhibits Co-Fe deposition if compared to sodium saccharin and saccharin. Néel coefficient calculated from the log-log plot of easy-axis coercivity (Hc) vs. film thickness in the range above 600 Aå are -0.23 and -0.3 for sodium saccharin and saccharin, respectively. On the other hand, Co-Fe ultra- thin films deposited from maltose-containing baths showed no dependence of Hc on films thickness in the same range. The uniaxial magnetic anisotropy induced during deposition was also investigated.
Electrodeposition of Laminated High-Bs CoNiFe Alloys by Current Density Modulation
Authors: Medina Jose A.
Published: August 2007

We demonstrate that high-Bs laminated CoNiFe alloys with improved soft magnetic properties can be deposited by plating current density modulation in a single plating bath. The laminated material consists of high-Bs CoNiFe layers with bcc crystal phase and thinner intermediate layers of softer CoNiFe with mixed fcc + bcc crystal phase. The electrodeposition method presented here offers advantages for laminated magnetic alloy fabrication over the use of multiple plating cells. These include simple plating hardware requirements and elimination of the risk for corrosion due to multiple substrate transfer steps.
Electroless Deposition of Thin-Film CoB alloys: The Influence of Some Bath Parameters on its Magnetic Behavior
Authors: Ribeiro Mauro C. , Sumodjo Paulo Teng An
Published: August 2007

The influence of citrate and glycine at different concentrations on the morphology and magnetic properties of thin film CoB alloys is studied. With both additives, coercivity (Hc) is inversely proportional to the complexant concentration. In deposits obtained from glycine containing baths higher magnetization saturation (Ms) values were obtained (1.3 T). Possibly the higher Ms in deposits grown from glycine baths is due to the low boron content (less than 1%). In deposits obtained in citrate containing baths, the boron content increased until a maximum of c.a. 15 % as the citrate concentration was increased. There are evidences that not only boron but the additive influences microstructure and therefore the magnetic properties of such films.
Cause of Damage of Reactive Ion Beam Etching for Ni-Fe films with CO/NH3 and CH3OH Chemicals
Authors: Watanabe Katsuro
Published: August 2007

The damage caused by reactive ion beam etching (RIBE) using CO/NH3 and CH3OH chemicals was investigated for Ni-Fe films thinner than 20 nm. Measurement of the changes in magnetization of films etched at a stage temperature from 40 to 100ºC and a bias power from 100 to 500 W revealed that the dominant damage with CO/NH3 was chemical, while that with CH3OH was physical. The amount of damage in the latter case was 1/3 to 1/2 that in the former case. The effect of RIBE on the soft magnetic properties was also investigated. A sample etched under conditions that cause a thicker damaged layer had a lower anisotropy field (Hk) and a lower easy axis coercive force (Hc). This indicates that RIBE degrades magnetic anisotropy in the Ni-Fe films.
Pulse Reversal PermAlloy Plating Process for MEMS Applications
Authors: Smistrup Kristian , Tang Peter T. , Mo̸ller Per
Published: August 2007

Nickel-iron, and especially Permalloy, plating has been known and used for more than 40 years, but there are still several problems related to stability and maintenance that should be resolved. This paper presents a saccharine-free pulse reversal plating Permalloy electrolyte, which gives low-stress deposits. We demonstrate selected MEMS applications of the electrolyte. The use of the strong complexing agent 5-sulfosalicylic acid allows for a photometric determination of the Fe3+-level in the bath and eliminate precipitates. This makes the electrolyte suitable as a Permalloy plating process used on an irregular basis.
Magnetoelectronical Sensors for Mechanical Measurements
Authors: Meyners D , Puchalla J , Dokupil S , Lohndorf M , Quandt Eckhard
Published: August 2007

Recently, highly sensitive strain gauges were developed, which are based on TMR (tunnel magnetoresistance) or GMR (giant magnetoresistance) effects combined with the inverse magnetostriction. GMR and TMR structures generally possess a symmetrical characteristic which reflects the switching fields of the soft and hard layers, respectively. This characteristic can be changed by a stress field if the soft layer is replaced by a suitable magnetostrictive layer leading to a stress induced rotation of the magnetostrictive layer with respect to the reference layer. In particular in combination with the TMR effect, this approach illustrates an interesting, highly sensitive mechanism in order to detect mechanical variables with a high spatial resolution as well as an unrivaled high gauge factor. In addition, the feasibility of an integrated fabrication compatible to cost effective fabrication routes using nano-/micro techniques is of great interest e.g. for the automotive industry. In this paper, the basics, the fabrication and the features of magnetoelectronical sensors will be discussed in view of an integrated pressure sensor for automotive applications.
A Concept for a Toolbox of Components for Modular Magnetic Microsensors
Authors: Gatzen H. H. , Hansen Stefan , Rissing Lutz
Published: August 2007

Magnetic micro sensors are capable of covering a range of functions, for instance measurement of distance, force, or material properties like magnetic behavior or surface defects. By coming up with a toolbox of sensor components for the basic functions and considering their technology compatibility, a modular micro sensor family has been created. Combining the appropriate building blocks allows to achieving the sensor function desired. To demonstrate the approach, components to facilitate a micro strain gauge sensor for force measurement and a sensor allowing to analyzing magnetic material properties were created and used to build up the respective micro sensors.
Direct Synthesis of Ferromagnetic Fe-Pt Nanoparticles By Using a High-Pressure Chemical Solution Route with Microwave Irradiation
Authors: Kitamoto Yoshitaka , Minami Rumiko , Chikata Tsukasa , Kato Shunsaku
Published: August 2007

We report direct synthesis of chemically ordered FePt nanoparticles using microwave irradiation during polyol reaction at 250 {degree sign}C under high pressure without any post- synthesis treatments. An X-ray diffraction pattern of as- synthesized FePt nanoparticles shows superlattice peaks. Mössbauer analysis exhibits the FePt nanoparticles having partially ordered L10 structure, and the fraction of Fe atoms in the chemically ordered L10 structure to the total amount of Fe atoms is 57 %. Coercivity and saturation magnetization of the partially ordered FePt nanoparticles are 3.4 kOe and 49 emu/g at room temperature, respectively. An evaluation of the anisotropy-field distribution using Flanders-Shtrikman method reveals that the FePt sample includes nanoparticles with anisotropy fields much lower than the anisotropy field HkWr of 85 kOe obtained by rotational hysteresis loss measurements.
Electrodeposition of FePt Embedded into Nanohole Structures for Magnetic Recording Media
Authors: Nakamura Takashi , Ichihara Shigeru , Den Tohru
Published: August 2007

FePt alloy films have been electrodeposited from a bath containing stable Fe complex. The annealing in atmosphere of H2 instead of vacuum results in the improvement of the L10 FePt properties because of the reduction of Fe oxide in the as- deposited films. The electrodeposited FePt alloy was uniformly embedded into nanohole templates such as anodized alumina films and phase separated AlSi films. The L10 ordered phase is formed in the nanohole structures.
CoFe, Fe and Co Nanoparticle Displacement with Cu Ions
Authors: Guo Zhanhu , Henry Laurence L. , Podlaha Elizabeth J.
Published: August 2007

The synthesis of iron-cobalt alloyed nanoparticles (3.8 + 0.3 nm) was reported by a wet chemical reduction method with a sulfobetaine surfactant. The surfactant is chemically bound onto the nanoparticle surface to prevent the agglomeration of nanoparticles and to render the nanoparticle soluble in an aqueous copper citrate electrolyte for the fabrication of a Cu shell. The effect of annealing was also examined as a means of decomposing the surfactant to create a carbon shell around the iron-cobalt nanoparticle. Both elemental analysis and magnetic properties were examined.
Electrodeposition and Electrochemical Etching of Au/CoAu Multilayered Nanowires
Authors: Guan Maoshi , Podlaha Elizabeth J.
Published: August 2007

Au/CoAu electrodeposition followed by etching of multilayered nanowires in nanoporous templates from a non-cyanide electrolyte was presented. The electrode used for etching was developed by releasing the nanowires from the template and fixing them on a carbon tape. By precisely controlling the electrochemical etching potential and time, the surface area of the nanowires can be enhanced. Nano-bamboo structures were created after partial etching and Au nanodisk structures were created after complete etching. Thus, selective anodization can be used to partially etch nanostructures in a controlled manner.
Magnetic Abrasive Finishing Using Nano-size Diamond Dispersed Co-Ni Electroless Plated Plastic Balls and its Application to Post CMP Process
Authors: Yoshihara Sachio , Hanzawa Keiko , Shirakashi Takashi
Published: August 2007

Magnetic Abrasive Particles (MAPs) were successfully prepared by a new technique based on the nickel-cobalt diamond composite plated plastic ball. The finishing results for Damascene samples proved the powerful ability of the new MAPs for application in fabricating electronic devices. In this report, a new process for the preparation of bound MAPs based on the electroless cobalt-nickel boron diamond composite plating on plastic balls is described. Here, plastic balls were used as a support for the growth of MAPs due to its lightweight properties. This work aims to develop lightweight and forceful MAPs. Magnetic field assisted finishing was performed to examine the fabricated MAPs. The AFM images showed the changes in the surface profile before and after finishing by cobalt-nickel diamond composite plated plastic balls for 10 minutes. The AFM images for the sample after MAF suggest that surface smoothing could be attained and that nano-level polishing could be achieved by this method.
Magnetic Assembly of Ferromagnetic Nanowires
Authors: Hangarter Carlos , Yoo Bong-Young , Rheem Youngwoo , Myung Nosang V. V.
Published: August 2007

Magnetic assembly of nanowires is summarized as a platform for device fabrication and nanowire characterization. This technique, as applied to the bottom up approach, is described in terms of nanowire synthesis, positioning, and electrical contact. Utilizing template directed electrodeposition multi- functional segmented nanowires can be fabricated, and a general sequence of ferromagnetic/functional/ferromagnetic segments can be used to incorporate a range of different materials with magnetic assembly technique. The use of magnetic dipole interactions for alignment is examined from initial nanowire chaining studies to site-specific assembly and hierarchical structures. Two methods of achieving electrical contact between nanowires and prefabricated electrodes, post annealing in a reduced environment and reflow of nanoscale solder, are discussed. The application of these components of magnetic assembly, template directed electrodeposition, magnetic alignment, and post assembly annealing, are also examined for demonstrating nanowire diameter dependent magneto-transport properties of nickel nanowires.
Influence of preconditioning-like hypoxia on the liver of developing methyl-deficient rats
Authors: Blaise Sébastien A. , Alberto Jean-Marc , Audonnet-Blaise Sandra , Guéant Jean-Louis , Daval Jean-Luc
Published: August 2007

Deficiency in nutritional determinants of homocysteine (HCY) metabolism, such as vitamin B12 and folate, during pregnancy is known to influence HCY levels in the progeny, which in turn may exert adverse effects during development, including liver defects. Since short hypoxia has been shown to induce tolerance to subsequent stress in various cells including hepatocytes, and as vitamins B deficiency and hypoxic episodes may simultaneously occur in neonates, we aimed to investigate the influence of brief postnatal hypoxia (100% N2 for 5 min) on the liver of rat pups born from dams fed a deficient regimen, i.e., depleted in vitamins B12, B2, folate, and choline. Four experimental groups were studied: control, hypoxia, deficiency, and hypoxia + deficiency. Although hypoxia transiently stimulated HCY catabolic pathways, it was associated with a progressive increase of hyperhomocysteinemia in deficient pups, with a fall of cystathionine β-synthase activity at 21 days. At this stage, inducible NO synthase activity was dramatically increased and glutathione reductase decreased, specifically in the group combining hypoxia and deficiency. Also, hypoxia enhanced the deficiency-induced drop of the S-adenosylmethionine/ S-adenosylhomocysteine ratio. In parallel, early exposure to the methyl-deficient regimen induced oxidative stress and led to hepatic steatosis, which was found to be more severe in pups additionally exposed to hypoxia. In conclusion, brief neonatal hypoxia may accentuate the long-term adverse effects of impaired HCY metabolism in the liver resulting from an inadequate nutritional regimen during pregnancy, and our data emphasize the importance of early factors on adult disease.
Novel role of the anorexigenic peptide neuromedin U in the control of LH secretion and its regulation by gonadal hormones and photoperiod
Authors: Vigo Eva , Roa Juan , Pineda Rafael , Castellano Juan M. , Navarro Victor M. , Aguilar Enrique , Pinilla Leonor , Tena-Sempere Manuel
Published: August 2007

Neuromedin U (NMU) is a widely spread neuropeptide, with predominant expression at the gastrointestinal tract and brain, putatively involved in the regulation of a diversity of biological functions, including food intake, energy balance and circadian rhythms; all closely related to reproduction. Yet, the implication of NMU in the control of the gonadotropic axis remains scarcely studied. We report herein analyses on the hypothalamic expression and function of NMU in different physiological and experimental states of the rat reproductive system. Expression of NMU mRNA at the hypothalamus was persistently detected along female postnatal development, with maximum levels in adulthood that fluctuated across the cycle and were modulated by ovarian steroids. Acute central administration of NMU evoked increases of serum LH levels in pubertal female rats, while repeated injection of NMU tended to advance vaginal opening. Likewise, central injection of NMU increased serum LH concentrations in cycling female rats, with peak responses in estrus. In contrast, NMU significantly inhibited preelevated LH secretion in gonadectomized and kisspeptin-treated rats. Finally, in noncycling females due to photoperiodic manipulation (constant light), hypothalamic NMU mRNA levels were markedly depressed, but relative LH responses to exogenous NMU were significantly augmented. All together, our present data support a predominant stimulatory role of NMU in the control of the female gonadotropic axis, which appears under the influence of developmental, hormonal, and photoperiodic cues, and might contribute to the joint regulation of energy balance, biological rhythms, and reproduction.
Macrophage Expression of Peroxisome Proliferator–Activated Receptor-α Reduces Atherosclerosis in Low-Density Lipoprotein Receptor–Deficient Mice
Authors: Babaev Vladimir R. , Ishiguro Hiroyuki , Ding Lei , Yancey Patricia G. , Dove Dwayne E. , Kovacs William J. , Semenkovich Clay F. , Fazio Sergio , Linton MacRae F.
Published: August 2007

Background—

The peroxisome proliferator–activated receptor-α (PPARα) plays important roles in lipid metabolism, inflammation, and atherosclerosis. PPARα ligands have been shown to reduce cardiovascular events in high-risk subjects. PPARα expression by arterial cells, including macrophages, may exert local antiatherogenic effects independent of plasma lipid changes.

Methods and Results—

To examine the contribution of PPARα expression by bone marrow–derived cells in atherosclerosis, male and female low-density lipoprotein receptor–deficient (LDLR
−/−
) mice were reconstituted with bone marrow from PPARα
−/−
or PPARα
+/+
mice and challenged with a high-fat diet. Although serum lipids and lipoprotein profiles did not differ between the groups, the size of atherosclerotic lesions in the distal aorta of male and female PPARα
−/−
→LDLR
−/−
mice was significantly increased (44% and 46%, respectively) compared with controls. Male PPARα
−/−
→LDLR
−/−
mice also had larger (44%) atherosclerotic lesions in the proximal aorta than male PPARα
+/+
→LDLR
−/−
mice. Peritoneal macrophages from PPARα
−/−
mice had increased uptake of oxidized LDL and decreased cholesterol efflux. PPARα
−/−
macrophages had lower levels of scavenger receptor B type I and ABCA1 protein expression and an accelerated response of nuclear factor-κB–regulated inflammatory genes. A laser capture microdissection analysis verified suppressed scavenger receptor B type I and increased nuclear factor-κB gene expression levels in vivo in atherosclerotic lesions of PPARα
−/−
→LDLR
−/−
mice compared with the lesions of control PPARα
+/+
→LDLR
−/−
mice.

Conclusions—

These data demonstrate that PPARα expression by macrophages has antiatherogenic effects via modulation of cell cholesterol trafficking and inflammatory activity.
Sources of Error in Dual-Wavelength Radar Remote Sensing of Cloud Liquid Water Content
Authors: Williams John K. , Vivekanandan J.
Published: August 2007

Dual-wavelength ratio (DWR) techniques offer the prospect of producing high-resolution mapping of cloud microphysical properties, including retrievals of cloud liquid water content (LWC) from reflectivity measured by millimeter-wavelength radars. Unfortunately, noise and artifacts in the DWR require smoothing to obtain physically realistic values of LWC with a concomitant loss of resolution. Factors that cause inaccuracy in the retrieved LWC include uncertainty in gas and liquid water attenuation coefficients, Mie scattering due to large water droplets or ice particles, corruption of the radar reflectivities by noise and nonatmospheric returns, and artifacts due to mismatched radar illumination volumes. The error analysis presented here consists of both analytic and heuristic arguments; it is illustrated using data from the Mount Washington Icing Sensors Project (MWISP) and from an idealized simulation. In addition to offering insight into design considerations for a DWR system, some results suggest methods that may mitigate some of these sources of error for existing systems and datasets.
Demonstration Measurements of Water Vapor, Cirrus Clouds, and Carbon Dioxide Using a High-Performance Raman Lidar
Authors: Whiteman David N. , Rush Kurt , Veselovskii Igor , Cadirola Martin , Comer Joseph , Potter John R. , Tola Rebecca
Published: August 2007

Profile measurements of atmospheric water vapor, cirrus clouds, and carbon dioxide using the Raman Airborne Spectroscopic lidar (RASL) during ground-based, upward-looking tests are presented here. These measurements improve upon any previously demonstrated using Raman lidar. Daytime boundary layer profiling of water vapor mixing ratio up to an altitude of approximately 4 km under moist, midsummer conditions is performed with less than 5% random error using temporal and spatial resolution of 2 min and 60–210 m, respectively. Daytime cirrus cloud optical depth and extinction-to-backscatter ratio measurements are made using a 1-min average. The potential to simultaneously profile carbon dioxide and water vapor mixing ratio through the boundary layer and extending into the free troposphere during the nighttime is also demonstrated.
Phase Coding for Range Ambiguity Mitigation in Dual-Polarized Doppler Weather Radars
Authors: Bharadwaj N. , Chandrasekar V.
Published: August 2007

This paper evaluates the retrieval of polarimetric variables when phase-coded waveforms are employed to suppress range overlaid echoes. A phase-coded waveform tags transmitted pulses with a phase code and then decodes the received signal to separate the overlaid echoes. Two methods suggested for separating overlaid echoes use random and systematic phase-coding techniques. In this paper, random phase and systematic phase-coded waveforms are evaluated for dual-polarized operation. The random phased-coded and systematic phase-coded waveforms are known to provide fairly good estimates of the Doppler spectral moments. This paper presents results at S band to quantify the performance of phase-coded waveform in retrieving polarimetric variables. It is shown that the polarimetric variables for both strong and weak trip echoes are estimated with acceptable accuracy.
Detection and Correction of Diurnal Sampling Bias in HIRS/2 Brightness Temperatures
Authors: Jackson Darren L. , Soden Brian J.
Published: August 2007

Diurnal sampling biases arise in the High-Resolution Infrared Radiation Sounder (HIRS) satellite observations because some of the NOAA polar-orbiting satellites drift significantly from their original local observation time. Such bias adversely affects interpretation of these data for climate studies. Twenty-six years of HIRS/2 radiance satellite data (1979–2004) were examined by creating monthly mean gridded data that categorize the observations by local observing time through averaging ascending and descending orbits separately. Corresponding HIRS/2 simulated radiance data from the Geophysical Fluid Dynamics Laboratory (GFDL) climate model were constructed using HIRS/2 satellite sampling and were found to accurately represent the diurnal sampling bias. Correction of the HIRS/2 observations from the observed diurnal sampling bias was using the model simulations of HIRS brightness temperatures to adjust the observed brightness temperatures to the model daily mean. The diurnal bias was found to vary with channel, surface type, latitude, satellite, and cloud cover, but showed little dependence on satellite scan angle. Diurnal bias is most pronounced for ascending orbit observations of the afternoon [1400 local solar time (LST)] satellites with 60°N to 60°S domain averaged brightness temperatures variations up to 0.78 K yr−1. Lower tropospheric temperature and water vapor channels contained the largest bias, and biases over land were more than twice as large as those over the ocean. Brightness temperature adjustments of up to 10 K were needed in the most extreme situations.
Spectral Wave–Turbulence Decomposition
Authors: Bricker Jeremy D. , Monismith Stephen G.
Published: August 2007

A new method of wave–turbulence decomposition is introduced, for which the only instrument required is one high-frequency pointwise velocity sensor. This is a spectral method that assumes equilibrium turbulence and no wave–turbulence interaction. Nonetheless, laboratory and field experiments show that the new method produces results in good agreement with the results of established wave–turbulence decomposition methods. Therefore, this spectral method proves useful when neither a synchronized wave gauge, nor a second velocimeter, is available. Furthermore, this study indicates that uncertainty in velocimeter probe orientation is responsible for most of the wave bias occurring in turbulent velocity data, so that an accurate measurement of this orientation makes wave–turbulence decomposition unnecessary.
An Ambivalent Legacy: Cardoso and Land Reform
Authors: Ondetti Gabriel
Published: August 2007

Few policies implemented during the presidency of Fernando Henrique Cardoso in Brazil provoked as much disagreement as land reform. While officials claimed to be undertaking a virtual revolution in the countryside, activists derided the program as little more than a palliative. Assessment of its extent and character drawing on a variety of sources indicates that many of the criticisms are on the mark. Only a small percentage of the landless population benefited, and those who did often lacked even minimal infrastructure or support services. At the same time, Cardoso settled more landless than all of his predecessors combined. His reform pales next to the major reforms in Latin American history, but it was one of the most ambitious programs carried out under democratic conditions that was not later reversed by a coup d'état. Cardoso's progress in this area was partly a result of two aspects of the political context at the start of his government: his own personal image as a progressive reformer and the growing strength of the Movimento dos Trabalhadores Rurais Sem Terra (Movement of Landless Rural Workers—MST). However, chance events also played a key role. Particularly important were two massacres of land reform protestors that occurred early in his first term, thrusting the land issue onto the political agenda at an opportune moment.
Fiscal Squeeze and Social Policy during the Cardoso Administration (1995—2002)
Authors: Vernengo Matías
Published: August 2007

Conventional wisdom associates the two lost decades of economic stagnation in Brazil to macroeconomic imbalances and excessive budgetary deficits. Contrary to conventional wisdom, the fiscal crisis of the state in Brazil was the result of the liberalization strategy that started in 1989 and was accelerated and complemented during the Cardoso administration (1995—2002). The fiscal crisis of the state resulted from the financial liberalization of the 1990s and the increasing burden of interest payments on public debt. The interest burden, in turn, meant that fiscal spending on social policy was squeezed, a result that is common in liberalization experiences in the periphery. The amount of social spending was insufficient during the Cardoso administration, and problems were not restricted to inefficient spending.
Least Squares Distance Method of Cognitive Validation and Analysis for Binary Items Using Their Item Response Theory Parameters
Authors: Dimitrov Dimiter M.
Published: August 2007

The validation of cognitive attributes required for correct answers on binary test items or tasks has been addressed in previous research through the integration of cognitive psychology and psychometric models using parametric or nonparametric item response theory, latent class modeling, and Bayesian modeling. All previous models, each with their advantages and disadvantages, require item score information and do not focus on conditional validation of cognitive attributes across ability levels and individual test items. This study proposes a method of estimating the probability of correct performance on cognitive attributes across fixed ability levels. The proposed method, referred to here as the least squares distance method (LSDM), is based on the minimization of matrix norms using the Euclidean least squares distance. The LSDM does not require raw or trait scores of examinees as long as IRT estimates of the item parameters are available.
A Monte Carlo Examination of the Sensitivity of the Differential Functioning of Items and Tests Framework for Tests of Measurement Invariance With Likert Data
Authors: Meade Adam W. , Lautenschlager Gary J. , Johnson Emily C.
Published: August 2007

This article highlights issues associated with the use of the differential functioning of items and tests (DFIT) methodology for assessing measurement invariance (or differential functioning) with Likert-type data. Monte Carlo analyses indicate relatively low sensitivity of the DFIT methodology for identifying differential item functioning (DIF) under some conditions of differential functioning with previously recommended significance values. The differential test functioning index was extremely insensitive to differential functioning under all study conditions. The authors recommend alternative noncompensatory DIF cutoff values used to evaluate the significance of DIF for different DIF effect sizes. Additionally, contrasts between polytomous and dichotomous data are drawn, and problems with determining measurement invariance at the scale, rather than item, level for Likert scale data are highlighted.
Proximal Tibial Opening Wedge Osteotomy as the Initial Treatment for Chronic Posterolateral Corner Deficiency in the Varus Knee
Authors: Arthur Andrew , LaPrade Robert F. , Agel Julie
Published: August 2007

Background

Nonoperative treatment of posterolateral knee injuries tends to yield poor results. In patients with chronic posterolateral knee injuries, failure to correct genu varus alignment will often result in failure of the posterolateral knee repair or reconstruction.

Purpose

To prospectively assess the functional outcomes of patients with combined grade 3 posterolateral instability and genu varus alignment initially treated with a proximal tibial opening wedge osteotomy.

Study Design

Cohort study (prognosis); Level of evidence, 2.

Methods

Twenty-one patients with combined chronic posterolateral corner deficiency and genu varus alignment were initially treated with a proximal tibial opening wedge osteotomy and observed prospectively. Second-stage ligamentous reconstruction was performed in patients with continued clinical and functional instability after the osteotomies had healed and they had undergone at least 3 months of rehabilitation.

Results

At a mean follow-up of 37 months, 8 of 21 patients (38%) had sufficient improvement in knee function that a subsequent posterolateral corner reconstruction was not necessary. There was a significant difference in coronal alignment between the preoperative and postoperative mechanical axis action point. There were no significant differences in the preoperative and postoperative posterior tibial slope. Thirteen patients underwent a second-stage ligament reconstruction at an average of 13.8 months after the initial osteotomy procedure. Final postoperative Cincinnati Knee Rating System scores were significantly lower for those patients who required a subsequent posterolateral corner reconstruction than for those patients who did not have a reconstruction. The P value for the preoperative differences between groups was not significant (P = .11). Seven of 9 patients with high-velocity knee injuries required a second-stage reconstruction. Ten of 14 patients (71%) with multiligament knee injuries required a posterolateral corner reconstruction. In contrast, 4 of 6 patients (67%) with an isolated posterolateral corner injury did not require a second-stage ligament reconstruction.

Conclusion

Proximal tibial opening wedge osteotomy can be an effective first method of treatment for patients with chronic combined posterolateral knee injuries and genu varus alignment. Patients with low-velocity knee injuries and isolated chronic posterolateral knee injuries may not require a second-stage soft tissue ligament reconstruction after healing the osteotomy and undergoing a program of rehabilitation.
Analysis of Cartilage Tissue on a Cellular Level in Fresh Osteochondral Allograft Retrievals
Authors: Williams Seth K. , Amiel David , Ball Scott T. , Allen R. Todd , Tontz William L. , Emmerson Bryan C. , Badlani Neil M. , Emery Shawn C. , Haghighi Parviz , Bugbee William D.
Published: August 2007

Background

Fresh human osteochondral allografting is a biological cartilage replacement technique used to treat articular and osteoarticular defects in the knee. A small number of grafts fail, and we analyzed every retrieved graft during a 4-year period in order to learn more about the potential causes of failure.

Hypothesis

A large percentage of chondrocytes still remain viable many years after fresh osteochondral allografting.

Study Design

Descriptive laboratory study.

Methods

Retrieval specimens were obtained at the time of revision surgery and immediately analyzed. Chondrocyte viability and viable cell density were determined using a live/dead staining technique followed by confocal microscopy. Glycosaminoglycan content was a measure of the cartilage matrix. Radiolabeled sulfate uptake served as a biochemical marker of chondrocyte metabolic activity. Cartilage and subchondral bone were examined histologically.

Results

Fourteen patients yielded a total of 26 retrieval specimens that had been originally implanted as individual fresh osteochondral allografts. Average graft survival was 42 months. Chondrocyte viability was 82% ± 17%, and chondrocyte viable cell density was 15 590 ± 5900 viable cells/mm3. Retrieved tissue demonstrated radiolabeled sulfate uptake of 437 ± 270 counts per minute and 3.5% ± 0.8% hexosamine per dry weight. Histologically, all specimens showed some degree of cartilage fibrillation. There was evidence of bone allograft incorporation in most specimens, as well as pannus formation in 4 specimens, but no evidence of immune rejection.

Conclusion

A small percentage of fresh osteochondral allografts fail, but the precise cause is unknown. The main theories for failure investigated here include immunologic rejection, failure of bony incorporation, and chondrocyte death causing breakdown of the cartilage matrix. We show that chondrocytes remain viable many years after transplantation, allograft bone incorporates, and immune rejection does not seem to play a primary role in failure.

Clinical Relevance

Fresh osteochondral allografting is becoming more common in the treatment of articular cartilage defects in the knee. Our findings support the paradigm of fresh osteochondral allografting, the transplantation of hyaline cartilage with biological incorporation of the underlying bone scaffold. The reasons for failure of a small percentage of grafts remain unclear.
Arthroscopic Autologous Osteochondral Grafting for Cartilage Defects of the Knee
Authors: Marcacci Maurilio , Kon Elizaveta , Delcogliano Marco , Filardo Giuseppe , Busacca Maurizio , Zaffagnini Stefano
Published: August 2007

Background

Articular cartilage lesions, with their inherent limited healing potential, remain a challenging problem for orthopaedic surgeons. Various approaches have been proposed to treat these lesions; nevertheless, opinions on indications and clinical efficacy of these techniques are still controversial.

Purpose

To evaluate the outcome of osteochondral autografts for treatment of femoral condyle cartilage lesions at a medium-to long-term follow-up.

Study Design

Case series; Level of evidence, 4.

Methods

We prospectively evaluated 30 patients (mean age, 29.3 years) with full-thickness knee chondral lesions (<2.5 cm2) treated with arthroscopic autologous osteochondral transplantation. Thirteen patients underwent previous surgery, while 17 patients were operated on for the first time. In 19 patients, associated procedures were performed. All patients were evaluated at 2- and 7-year follow-up. The International Cartilage Repair Society form, Tegner score, and magnetic resonance imaging were used for clinical evaluation.

Results

The International Cartilage Repair Society objective evaluation showed 76.7% of patients had good or excellent results at 7-year follow-up, and International Knee Documentation Committee subjective score significantly improved from preoperative (34.8) to 7-year follow-up (71.8). The Tegner evaluation showed a significant improvement after the surgery at 2- and 7-year follow-up (from 2.9 to 6.2 and 5.6, respectively); however, we noticed reduced sports activity from 2- to 7-year follow-up. Magnetic resonance imaging evaluation showed good integration of the graft in the host bone and complete maintenance of the grafted cartilage in more than 60% of cases.

Conclusion

The results of this technique at medium- to long-term follow-up are encouraging. This arthroscopic 1-step surgery appears to be a valid solution for treatment of small, grade III to IV cartilage defects.