bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanosecond Imaging of Bubble Nucleation on a Microheater
Authors: Avedisian C. Thomas , Cavicchi Richard E. , Tarlov Michael J.
Published: August 2006

These images show bubble nucleation and growth of a thin film heater (a platinum film 15 μm wide, 30 μm long and 0.2 μm thick) that is heated by an 11.8 volt pulse of 0.50 μs duration in subcooled water. Imaging is by illumination from a Nd:Yag laser (hence the green colored photographs) that produces an effective frame rate of 1.3×108 frames/s (the method is described in Avedisian et al. (2006) and Balss et al. (2005)). Time is relative to the first appearance of bubbles. In the early phase, bubbles are visible at the four corners of the platinum surface (58 ns) which grow laterally into a vapor film (142 ns) that covers the surface by 178 ns after which the bubble thickens and grows into the bulk (246 ns and beyond). The collapse phase (e.g., 3.5 μs to 3.8 μs) continues well after the heater pulse is turned off. Vapor completely disappears (3.65 μs) but then bubbles reappear (3.8 μs) well after the power-off phase. Reappearance of bubbles is speculated to be the result of a stagnation-like flow induced by the rapid collapse and inward motion of liquid that jets upward to cause a local reduction of pressure to cavitate a bubble at 3.8 μs. [Avedisian, C.T., Cavicchi, R.E., Tarlov, M.J., Rev. Sci. Instruments, 2006, in press; Balss, K.M., Avedisian, C.T., Cavicchi, R.E., Tarlov, M.J., Langmuir, 21, 10459–10467 (2005)]
Evaporation and Dryout of Nanofluid Droplets on a Microheater Array
Authors: Chon C. H. , Paik S. W. , Tipton J. B. , Kihm K. D.
Published: August 2006

Nanofluid, a mixture of small concentration of metallic nanoparticles in a base fluid, is known to have substantial enhancement in thermal conductivity compared with that of the base fluid. The evaporation processes of different nanofluid droplets, all for 5-μl, 0.5 vol. % concentration and onto the micro-heater array at 80°C, are visualized to examine the effect of nanoparticle sizes on the dryout characteristics. While the distilled water droplet evaporates evenly in an axi-symmetric way, dryout patterns of the nanofluids containing nanoparticles (2-nm Au, 30-nm CuO, and 11-nm and 47-nm diameter Al2O3) are different in leaving concentric rims of dried nanoparticles near the initial wet-surface boundary. The formation of the rim is the most distinctive for the case of nanofluid containing 47-nm Al2O3, whereas the rims are less pronounced and more spreading for nanofluids containing smaller nanoparticles. For nanofluid containing 2-nm Au particles, the deposition is thicker and more uniform toward the droplet inner area in comparison with the other nanofluids containing larger nanoparticles. This is believed to be due to its slower flow and higher viscosity as a result of higher particle population, and high specific gravity.
Mili-Scale Visualization of Bubble Growth-Translation and Droplet Impact Dynamics
Authors: Manglik R. M. , Jog M. A. , Subramani A. , Gatne K.
Published: August 2006

The dynamic behavior of an air bubble, emanating from a 0.32 mm i.d., 0.64 mm o.d., vertical capillary-tube orifice with a bubble interval of 0.22–0.28 s at constant pressure and adiabatic (T=25°C) conditions, as well as droplet impact and spreading on a hydrophobic surface are characterized. Images of the mili-scale spatial-temporal evolution of bubbles (embryonic appearance at orifice tip → growth and detachment → translation) as well as droplets were acquired using a high-speed (5000 frames/s) digital video camera fitted with a 8× optical zoom lens. It was triggered through a computer interface to record continuous high-speed video from which any desired frame can be captured by digital-video-processing software; the equivalent departure diameter was estimated by area-averaging using image processing software. The impact, spreading, and recoil behaviors of ethanol and water droplets on a horizontal stainless steel surface are depicted in Fig. 1. For constant Weber number (We∼10), the spreading and recoil dynamics in the two cases are significantly different. Higher wettability of ethanol promotes greater spreading and dampens recoil in comparison with that seen in water. Figure 2 depicts the growth of an air bubble in pools of ethanol and water. While displaying similar ebullience, a bubble of smaller size and surface age is produced in low-surface-tension ethanol. Dynamic shape variations of the air bubble as it translates upwards in the pool are seen in Fig. 3. From a nearly spherical, tear-drop bubble, the shape changes to an oblate ellipsoid during translation, and surface tension effects are manifest only in the size of respective bubbles.
The Passing Behaviors of Vapor through Cloth
Authors: Narumi Akira , Uchida Kenichi , Konishi Tadashi
Published: August 2006

There occurs heat and mass transfer through cloth in the very small space from skin to the outside of cloth due to the release of heat and sweat evaporation from human body. The new simultaneous 2-D measurement technique of temperature and concentration distributions that combines infrared absorbing method (IR) with holographic interferometry (HI) was applied to this space. Cotton (porosity Φ=0.586, thickness t=324μm) and nylon (Φ=0.578, t=347μm) were used for the typical hydrophilic and hydrophobic clothes, respectively. N-propanol was used for liquid. The distance from liquid surface to cloth was 5mm. Liquid temperature was 40°C. The superimposed images of HI and IR show clearly that more vapor passes through cloth in the case of cotton than in the case of nylon. This fact demonstrates that this new technique is very useful for measuring the passing behaviors of vapor through cloth. We appreciate that this research was partially supported by funds of Grant-in-Aid for Scientific Research in Japan.
Effects of Intersection Angles on Flow and Heat Transfer in Corrugated-Undulated Channels With Sinusoidal Waves
Authors: Yin Jixiang , Li Guojun , Feng Zhenping
Published: August 2006

This paper reported three-dimensional numerical simulations of the steady laminar flow and heat transfer in corrugated-undulated channels with sinusoidal waves, aiming to investigate the effects of intersection angles (θ) between corrugated and undulated plate and Reynolds number (Re) on the flow and heat transfer. The simulations are conducted by using multi-channel computational domain for three different geometries. The code is validated against experimental results and then data for Nusselt number (Nu) and friction factor (f) are presented in a Re range of 100-1500, and intersection angle range of 30-150deg. The simulation confirms the changes of Nuu (averaged over undulated plate) and Nuc (averaged over corrugated plate) with θ representing different characteristics. As θ increases, Nu (Nuu or Nuc) is about 2–16 times higher for the corrugated-undulated configurations CP-UH1 and CP-UP1 and the concomitant f is about 4–100 higher, when compared to a straight channel having square cross section. The minimum of local Nu ( Nuu or Nuc ) is situated at the four contact points where the top plate touches the bottom one, and the high Nu is located upstream of the crest of the conjugate duct. Performance evaluation for the CP-UH1 channel shows that the goodness factors (G) are larger than 1 with the straight channel having a square cross section as a reference, and the 30deg geometry channel has optimal flow area goodness.
Comparison
of Various Methods for Simultaneous Retrieval of Surface Emissivities and Gas Properties in Gray
Participating Media
Authors: Deiveegan M. , Balaji C. , Venkateshan S.
P.
Published: August 2006

An inverse radiation analysis for simultaneous estimation of the radiative properties and the surface emissivities for a participating medium in between infinitely long parallel planes, from the knowledge of the measured temperatures and heat fluxes at the boundaries, is presented. The differential discrete ordinate method is employed to solve the radiative transfer equation. The present analysis considers three types of simple scattering phase functions. The inverse problem is solved through minimization of a performance function, which is expressed by the sum of squares of residuals between calculated and observed temperatures and heat fluxes at the boundaries. To check the performance and accuracy in retrieval, a comparison is presented between four retrieval methods, viz. Levenberg-Marquardt algorithm, genetic algorithm, artificial neural network, and the Bayesian algorithm. The results of the present analyses indicate that good precision in retrieval could be achieved by using only temperatures and heat fluxes at the boundaries. The study shows that the radiative properties of medium and surface emissivities can be retrieved even with noisy data using Bayesian retrieval algorithm and artificial neural network. Also, the results demonstrate that genetic algorithms are not efficient but are quite robust. Additionally, it is observed that an increase in the error in measurements significantly deteriorates the retrieval using the Levenberg-Marquardt algorithm.
Direct Simulation of Transport in Open-Cell Metal Foam
Authors: Krishnan Shankar , Murthy Jayathi Y. , Garimella Suresh V.
Published: August 2006

Flows in porous media may be modeled using two major classes of approaches: (a) a macroscopic approach, where volume-averaged semiempirical equations are used to describe flow characteristics, and (b) a microscopic approach, where small-scale flow details are simulated by considering the specific geometry of the porous medium. In the first approach, small-scale details are ignored and the information so lost is represented in the governing equations using an engineering model. In the second, the intricate geometry of the porous structures is accounted for and the transport through these structures computed. The latter approach is computationally expensive if the entire physical domain were to be simulated. Computational time can be reduced by exploiting periodicity when it exists. In the present work we carry out a direct simulation of the transport in an open-cell metal foam using a periodic unit cell. The foam geometry is created by assuming the pore to be spherical. The spheres are located at the vertices and at the center of the unit cell. The periodic foam geometry is obtained by subtracting the unit cell cube from the spheres. Fluid and heat flow are computed in the periodic unit cell. Our objective in the present study is to obtain the effective thermal conductivity, pressure drop, and local heat transfer coefficient from a consistent direct simulation of the open-cell foam structure. The computed values compare well with the existing experimental measurements and semiempirical models for porosities greater than 94%. The results and the merits of the present approach are discussed.
Heat Transfer and Bubble Movement of Two-Side and One-Side Heating
Subcooled Flow Boiling in Vertical Narrow Channels
Authors: Pan Liang-Ming , Jen Tien-Chien , He Chuan , Xin Ming-dao , Chen Qing-hua
Published: August 2006

This paper investigates the bubble behavior of different heating methods of narrow rectangular channels. Comparisons were made on the onset of nucleate boiling (ONB) point and bubble behavior with various flow patterns. Results reveal that the wall superheat of two-side heating is lower than that in one-side heating at the same heat flux. This difference becomes obvious at a higher heat flux. Under the same subcooling condition, the required heat flux to start nucleate boiling for the one-side heating channel is higher than that for the two-side one. With similar bubbles behaviors, the cross-sectional subcooling tends to be higher for the two-side heating method.
A Theoretical Investigation Into the Optimal Longitudinal Profile of
a Horizontal Pin Fin of Least Material Under the Influence of Pure Forced and
Pure Natural Convection With a Diameter-Variable Convective Heat Transfer
Coefficient
Authors: Kobus C. J. , Cavanaugh R. B.
Published: August 2006

The increased importance of heat sinks in electronic cooling applications has resulted in a revived interest in extended surfaces, or fins. Also, space and cost constraints provide impetus for optimizing thermal performance for a given, or least, amount of material. The current research focuses on a pin fin design of least material, where the diameter of the pin fin varies axially to maintain the axial heat flux constant; thus all fin material is utilized equally. Although such fins have been studied in the past, the convective heat transfer coefficient was assumed to be constant, which is not entirely true since it is known to be a function of diameter for cylindrical bodies. The current research shows that an optimal fin based on a variable convective heat transfer coefficient yields a true optimal profile, and utilizes material better; that is, it uses a lower volume of material to achieve the same heat dissipation rate. This improvement in material utilization is show to be anywhere from approximately 3% to 14%.
Enzyme-Linked Immunosorbent Assay for Measuring Antibodies to Pneumococcal Polysaccharides for the PNEUMOVAX 23 Vaccine: Assay Operating Characteristics and Correlation to the WHO International Assay
Authors: Marchese Rocio D. , Jain Neil T. , Antonello Joseph , Mallette Laura , Butterfield-Gerson Kristin L. , Raab Jennifer , Burke Pamela , Schulman Cheryl , Adgate Hilary , Sikkema Daniel J. , Chirmule Narendra
Published: August 2006

The Merck pneumococcal (Pn) enzyme-linked immunosorbent assays (ELISAs) for measuring antibodies to 12 serotypes (serotypes 1, 3, 4, 6B, 7F, 8, 9V, 12F, 14, 18C, 19F, and 23F) were validated in 1999. Merck Laboratories developed the Pn assays using 10 μg/ml C polysaccharide, 100 μg/ml Pn polysaccharide (PnPs) 25, and 100 μg/ml PnPs 72 for preadsorption of samples, standards, and controls in order to improve the specificity to the Pn serotypes in the vaccine. The Pn assays utilize postimmunization sera obtained from subjects immunized with PNEUMOVAX 23 as standards for measuring immunoglobulin G concentrations in sera obtained from vaccine clinical trials with adults and infants. This material was calibrated to the Pn reference standard serum, 89SF, subjected to the Merck Pn ELISA adsorbants. Comparisons were made between the Merck Pn assay and the international Pn assay, showing moderate agreement between the two assay formats. This work describes the test procedures and operating characteristics of the Merck Pn assays and the results of experiments performed to compare the Merck Pn ELISAs to the international Pn ELISAs.
Human Neutralizing Fab Molecules against Severe Acute Respiratory Syndrome Coronavirus Generated by Phage Display
Authors: Kang Xiaoping , Yang Bao-an , Hu Yuyang , Zhao Hui , Xiong Wei , Yang Yinhui , Si Bingyin , Zhu Qingyu
Published: August 2006

Human recombinant Fab fragments specific for the spike protein of severe acute respiratory syndrome coronavirus (SARS-CoV) were screened from a human Fab library, which was generated from RNAs from peripheral lymphocytes of convalescent SARS patients. Among 50 randomly picked clones, 12 Fabs specially reacted with S protein by an enzyme-linked immunosorbent assay. The microneutralizing test showed that one clone, designated M1A, had neutralizing activity on Vero E6 cells against SARS-CoV. DNA sequence analysis indicated that the light- and heavy-chain genes of M1A Fab belong to the κ2a and 4f families, respectively. A neutralizing test on purified M1A demonstrated that 0.5 mg/ml of M1A completely inhibited SARS-CoV activity, with an absence of cytopathic effect for 7 days. Real-time fluorescence reverse transcription-PCR also proved the neutralizing capacity of M1A. These data showed that the number of virus copies was significantly reduced in the M1A-treated group, suggesting an important role for M1A in passive immunoprophylaxis against the SARS virus.
Quantitative Analysis of Levels of Serum Immunoglobulin G against Botulinum Neurotoxin Type D and Association with Protection in Natural Outbreaks of Cattle Botulism
Authors: Steinman A. , Chaffer M. , Elad D. , Shpigel N. Y.
Published: August 2006

The recent outbreaks of cattle botulism in vaccinated Israeli dairy cattle prompted us to determine vaccine efficacy and reasons for vaccine failure. Analysis of clinical signs, feeding practice, vaccination history, and epidemic curves enabled us to define a study population in two outbreaks, where high doses of
Clostridium botulinum
neurotoxin type D (BoNT/D) were evenly consumed by the affected animal groups. Attack rates among unvaccinated 6- to 24-month-old heifers were 96% (55/57) and 85% (53/62). The attack rates in vaccinated parity 1, 2, and ≥3 cows were 40.4% (21/52), 14.3% (4/28), and 5.6% (3/54), respectively. Vaccine efficacies for these cow groups were 52.5%, 83.2%, and 93.4%, respectively. In younger, unvaccinated 2- to 6-month-old calves, presumably protected by maternal antibodies, the attack rate was 24% (17/71). These differences correlated with significant differences in levels of specific anti-BoNT/D antibody in serum by an enzyme-linked immunosorbent assay (ELISA). The ELISA performance for predicting protection was analyzed by receiver operating characteristic analysis and was found to be highly significant, with an area under the curve of 0.941 (standard error, 0.034; 95% confidence interval, 0.875 to 1.008;
P
< 0.000). No animals with serum ELISA unit levels above 0.33 were affected in these exposed groups. At this cutoff level, the specificity of the ELISA was 100%, sensitivity was 67%, and accuracy was 92%. We concluded that botulinum toxoids can confer adequate protection against natural exposure to lethal doses of BoNT/D; however, the vaccination protocols should be optimized. Our in-house ELISA system will enable us to optimize vaccination protocols in the animal population.
Identification and Characterization of Immunogenic Proteins of
Mycoplasma genitalium
Authors: Svenstrup Helle Friis , Jensen Jørgen Skov , Gevaert Kris , Birkelund Svend , Christiansen Gunna
Published: August 2006

Mycoplasma genitalium
causes nonchlamydial nongonococcal urethritis.
M. genitalium
was detected by PCR in 17 urethral swabs obtained from 99 men with and without urethritis (J. S. Jensen, R. Orsum, B. Dohn, S. Uldum, A. M. Worm, and K. Lind, Genitourin. Med. 69:265-269, 1993), and later, four
M. genitalium
strains were isolated (J. S. Jensen, H. T. Hansen, and K. Lind, J. Clin. Microbiol. 34:286-291, 1996). The objective of this study was to characterize immunogenic proteins of
M. genitalium
by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting by using a hyperimmune rabbit serum against
M. genitalium
G37, determine their identity by mass spectrometry, and develop an
M. genitalium
-specific enzyme-linked immunosorbent assay (ELISA) free from cross-reactivity with
M. pneumoniae
antibodies. Using recombinant fragments of the C-terminal part of MgPa (rMgPa), we developed a specific ELISA for detection of
M. genitalium
antibodies. This antigen did not bind
M. pneumoniae
antibodies. Using serum samples from the 99 men with and without urethritis, we found that 26 had immunoglobulin G (IgG) antibodies to
M. genitalium
. There was a strong statistically significant correlation between PCR and IgG antibodies to
M. genitalium
(odds ratio [OR], 5.9; 95% confidence interval [CI], 2.3 to 21.5;
P
= 0.002). Furthermore, men with recurrent urethritis were more likely to have antibodies to
M. genitalium
than were those without recurrent urethritis (OR, 4.0; 95% CI, 1.1 to 14.5;
P
= 0.0383) and they had significantly higher antibody titers. By use of the rMgPa ELISA, this study further substantiates the importance of
M. genitalium
as a cause of male urethritis.
Influenza Virus NS Vectors Expressing theMycobacterium tuberculosisESAT-6 Protein Induce CD4+Th1 Immune Response and Protect Animals against Tuberculosis Challenge
Authors: Sereinig Sabine , Stukova Marina , Zabolotnyh Natalia , Ferko Boris , Kittel Christian , Romanova Julia , Vinogradova Tatiana , Katinger Hermann , Kiselev Oleg , Egorov Andrej
Published: August 2006

Infection withMycobacterium tuberculosisremains a major cause of morbidity and mortality all over the world. Since the effectiveness of the only available tuberculosis vaccine,Mycobacterium bovisbacillus Calmette-Guérin (BCG), is suboptimal, there is a strong demand to develop new tuberculosis vaccines. As tuberculosis is an airborne disease, the intranasal route of vaccination might be preferable. Live influenza virus vaccines might be considered as potential vectors for mucosal immunization against various viral or bacterial pathogens, includingM. tuberculosis. We generated several subtypes of attenuated recombinant influenza A viruses expressing the 6-kDa early secretory antigenic target protein (ESAT-6) ofM. tuberculosisfrom the NS1 reading frame. We were able to demonstrate the potency of influenza virus NS vectors to induce anM. tuberculosis-specific Th1 immune response in mice. Moreover, intranasal immunization of mice and guinea pigs with such vectors induced protection against mycobacterial challenge, similar to that induced by BCG vaccination.
Early Appearance of Bactericidal Antibodies after Polysaccharide Challenge of Toddlers Primed with a Group C Meningococcal Conjugate Vaccine: What Is Its Role in the Maintenance of Protection?
Authors: Tsai Theodore F. , Borrow Ray , Gnehm Hanspeter E. , Vaudaux Bernard , Heininger Ulrich , Desgrandchamps Daniel , Aebi Christoph , Balmer Paul , Pedersen Ronald D. , Fritzell Bernard , Siegrist Claire-Anne
Published: August 2006

The contribution of memory responses after meningococcal vaccination to protection may depend on the rapidity of the response. Toddlers were challenged with a licensed polysaccharide (PS) vaccine 1 year after vaccination with a single dose of meningococcal group C-CRM
197
conjugate (MCC) vaccine at the age of 12 to 15 months. Bactericidal antibodies and immunoglobulin G (IgG) antibodies detected by an enzyme-linked immunosorbent assay (ELISA) were measured before challenge and 4, 7, 14, or 21 Days later (“Days” refer to treatment groups, “days” to sampling days). Among 281 subjects in the intent-to-treat population, 173 per-protocol (PP) subjects were challenged with 10 μg PS antigen and 103 others with a 50-μg PS vaccinating dose. Capsular PS-specific ELISA IgG titers were negligible in baseline samples and increased only twofold within 4 days of PS administration. In contrast, the proportion of PP subjects with serum bactericidal antibody (SBA) titers of ≥1:8 or ≥1:128 increased, respectively, from 41% and 16% before challenge to 84% and 74% at Day 4 and to 100% and 97% at Day 7. Recipients of 50 μg PS responded with similar kinetics but showed a trend toward higher antibody levels. Unexpectedly, 69% of subjects bled on days 2 to 3 already had achieved SBA titers of ≥1:8. The majority of toddlers previously immunized with MCC and challenged 1 year later with PS antigen mounted protective levels of bactericidal antibody within 2 to 4 days.
Plant-Produced Cottontail Rabbit Papillomavirus L1 Protein Protects against Tumor Challenge: a Proof-of-Concept Study
Authors: Kohl T. , Hitzeroth I. I. , Stewart D. , Varsani A. , Govan V. A. , Christensen N. D. , Williamson A.-L. , Rybicki E. P.
Published: August 2006

The native cottontail rabbit papillomavirus (CRPV) L1 capsid protein gene was expressed transgenically viaAgrobacterium tumefacienstransformation and transiently via a tobacco mosaic virus (TMV) vector inNicotianaspp. L1 protein was detected in concentrated plant extracts at concentrations up to 1.0 mg/kg in transgenic plants and up to 0.4 mg/kg in TMV-infected plants. The protein did not detectably assemble into viruslike particles; however, immunoelectron microscopy showed presumptive pentamer aggregates, and extracted protein reacted with conformation-specific and neutralizing monoclonal antibodies. Rabbits were injected with concentrated protein extract with Freund's incomplete adjuvant. All sera reacted with baculovirus-produced CRPV L1; however, they did not detectably neutralize infectivity in an in vitro assay. Vaccinated rabbits were, however, protected against wart development on subsequent challenge with live virus. This is the first evidence that a plant-derived papillomavirus vaccine is protective in an animal model and is a proof of concept for human papillomavirus vaccines produced in plants.
Porcine Circovirus Type 2 Infection Decreases the Efficacy of a Modified Live Porcine Reproductive and Respiratory Syndrome Virus Vaccine
Authors: Opriessnig T. , McKeown N. E. , Harmon K. L. , Meng X. J. , Halbur P. G.
Published: August 2006

Porcine reproductive and respiratory syndrome virus (PRRSV)-induced pneumonia is a major problem, and vaccination is used to reduce losses associated with PRRSV. Porcine circovirus type 2 (PCV2) causes lymphoid depletion, and there is concern that this adversely affects the immune response. The objective of this study was to investigate the effect of PCV2 infection on the efficacy of modified live virus (MLV) PRRSV vaccine. Sixty-nine 2-week-old pigs were randomly assigned to one of seven groups of 9 to 10 pigs each. At 6 weeks of age, pigs in groups 4, 5, and 6 were inoculated intranasally with PCV2 ISU-40895. At 8 weeks of age, groups 3, 4, 6, and 7 were vaccinated with a PRRSV MLV vaccine. At 12 weeks of age, groups 2, 3, and 4 were challenged with PRRSV SDSU73. All pigs were necropsied 14 days after PRRSV challenge. PCV2-infected, PRRSV-vaccinated, and PRRSV-challenged pigs had significantly (P< 0.05) more-severe macroscopic lung lesions than did the PRRSV-vaccinated and PRRSV-challenged pigs that were not exposed to PCV2 prior to PRRSV vaccination. Nonvaccinated PRRSV-infected pigs had a significantly (P< 0.001) higher incidence of PRRSV antigen in lungs than did all other groups except the group infected with PCV2 prior to PRRSV vaccination and challenge. The nonvaccinated PRRSV-challenged group and the group challenged with PCV2 prior to PRRSV vaccination and challenge had significantly (P< 0.001) lower average daily weight gain than did the control and the vaccinated groups. This work suggests that PCV2 infection has an adverse effect on the development of protective immunity induced by PRRSV vaccine.
Regulation of Lipopolysaccharide-Induced Interleukin-12 Production by Activation of Repressor Element GA-12 through Hyperactivation of the ERK Pathway
Authors: Saito Shinji , Matsuura Motohiro , Hirai Yoshikazu
Published: August 2006

Interleukin-12 (IL-12) functions as a representative lipopolysaccharide (LPS) mediator in both innate and adaptive immunity. We investigated the regulation of LPS-induced IL-12 production by mouse macrophages. In response to LPS, peritoneal macrophages produced bioactive IL-12 p70, a heterodimer (p40/p35) of subunits, but macrophage lines such as J774.1 and RAW264.7 did not. Induction of the p35 subunit was impaired in both cell lines, and additional impairment of p40 induction was observed in RAW264.7 cells. These results suggest that some negative regulatory mechanisms against LPS-induced IL-12 p40 production are constitutively functioning in RAW264.7 cells but not in the other types of cells. Activation of GA-12 (a repressor element of IL-12 p40), rather than suppression of promoter elements, such as binding sites for NF-κB, AP-1, and IRF-1, was detected in LPS-stimulated RAW264.7 cells, accompanying hyperactivation of extracellular signal-related kinase (ERK). When ERK activation was suppressed by an inhibitor (U0126), production of p40 rose from an undetectable to a substantial level and GA-12 activation decreased. In peritoneal macrophages, stimulation with a high dose of LPS reduced p40 production with enhanced activation of ERK. Pretreatment of the cells with phorbol myristate acetate to enhance ERK activation reduced p40 production in response to the optimal LPS stimulation. Taken together, these results demonstrate that hyperactivation of the ERK pathway plays a role in upstream signaling for the activation of GA-12, leading to the repression of IL-12 p40 production in mouse macrophages.
Association of CD14 Promoter Polymorphism with Otitis Media and Pneumococcal Vaccine Responses
Authors: Wiertsema S. P. , Khoo S.-K. , Baynam G. , Veenhoven R. H. , Laing I. A. , Zielhuis G. A. , Rijkers G. T. , Goldblatt J. , LeSouëf P. N. , Sanders E. A. M.
Published: August 2006

Innate immunity is of particular importance for protection against infection during early life, when adaptive immune responses are immature. CD14 plays key roles in innate immunity, including in defense against pathogens associated with otitis media, a major pediatric health care issue. The T allele of the CD14 C-159T polymorphism has been associated with increased serum CD14 levels. Our objective was to investigate the hypothesis that the CD14 C-159T allele is protective against recurrent acute otitis media in children. The association between the CD14 promoter genotype and the number of acute otitis media episodes was evaluated both retrospectively and prospectively in a cohort of 300 children. Serotype-specific immunoglobulin G (IgG) antibody responses after pneumococcal vaccinations were examined according to CD14 genotype to compare immune responsiveness across genotypes. An age-dependent association was found: compared with that for CC homozygotes aged between 12 to 24 months, TT homozygotes had fewer episodes of acute otitis media (79 versus 41%, respectively;P= 0.004); this relationship was absent in older children. Additionally, TT homozygotes showed higher serotype-specific anti-pneumococcal IgG antibody levels. Our data suggest that genetic variation in CD14, a molecule at the interface of innate and adaptive immune responses, plays a key role in the defense against middle ear disease in childhood and in pneumococcal vaccine responsiveness. These findings are likely to be important to these and other immune-mediated outcomes in early life.
A Novel Double-Antigen Sandwich Enzyme-Linked Immunosorbent Assay for Measurement of Antibodies against Rabies Virus
Authors: Yang Li-Min , Zhao Liang-Zhen , Hu Rong-Liang , Shi Zhen-Sheng , Liu Wen-Jun
Published: August 2006

A novel double-antigen sandwich enzyme-linked immunosorbent assay (ELISA) was developed to measure rabies antibodies in dogs. In contrast to the 4 days required for detecting rabies antibody with conventional rabies antibody virus neutralization assays, this ELISA can be completed in hours, without using live virus, in routine laboratories.
Mycobacterium tuberculosis
HBHA Protein Reacts Strongly with the Serum Immunoglobulin M of Tuberculosis Patients
Authors: Shin A-Rum , Lee Kil-Soo , Lee Ji-Sook , Kim Su-Young , Song Chang-Hwa , Jung Saet-Byel , Yang Chul-Su , Jo Eun-Kyeong , Park Jeong-Kyu , Paik Tae-Hyun , Kim Hwa-Jung
Published: August 2006

Identification and characterization of serologically active mycobacterial antigens are prerequisites for the development of diagnostic reagents. We examined the humoral immune responses of active tuberculosis (TB) patients against Triton-soluble proteins extracted from
Mycobacterium tuberculosis
by immunoblotting. A 29-kDa protein reacted with immunoglobulin M (IgM) in the pooled sera of the patients, and its N-terminal amino acid sequence matched that of the heparin-binding hemagglutinin (HBHA). Recombinant full-length HBHA was expressed in
Escherichia coli
(rEC-HBHA) and
M. smegmatis
(rMS-HBHA). In immunoblot analysis, the IgM antibodies of the TB patients reacted strongly with rMS-HBHA but not with rEC-HBHA, whereas the IgG antibodies of these patients reacted weakly with both recombinant HBHA proteins. In enzyme-linked immunosorbent assay analysis using rMS-HBHA and 85B as antigens, the mean levels and sensitivities of the anti-HBHA IgM antibodies of the TB patients were significantly higher than those of the anti-antigen 85B IgM antibodies, while the IgG antibodies showed the opposite results. Of interest in this respect, the pooled sera from the TB patients that contained anti-HBHA IgM antibodies neutralized the entry of
M. tuberculosis
into epithelial cells. These findings suggest that IgM antibody to HBHA may play a role in protection against extrapulmonary dissemination.
Group B Streptococcal Type II and III Conjugate Vaccines: Physicochemical Properties That Influence Immunogenicity
Authors: Michon Francis , Uitz Catherine , Sarkar Arun , D'Ambra Anello J. , Laude-Sharp Maryline , Moore Samuel , Fusco Peter C.
Published: August 2006

Recent efforts toward developing vaccines against group B streptococci (GBS) have focused on increasing the immunogenicity of GBS polysaccharides by conjugation to carrier proteins. However, partial depolymerization of GBS polysaccharides for the production of vaccines is a difficult task because of their acid-labile, antigenically critical sialic acids. Here we report a method for the partial depolymerization of type II and III polysaccharides by mild deaminative cleavage to antigenic fragments with reducing-terminal 2,5-anhydro-d-mannose residues. Through the free aldehydes of their newly formed end groups, the fragments were conjugated to tetanus toxoid by reductive amination. The resulting conjugates stimulated the production in animals of high-titer type II- and III-specific antibodies which induced opsonophagocytic killing of type II and III strains of group B streptococci. For the type II conjugates, immunogenicity increased as oligosaccharide size decreased, whereas for type III conjugates, the size of the oligosaccharides did not significantly influence immunogenicity. When oligosaccharides of defined size were conjugated through sialic acid residues, the resulting cross-linkages were shown to affect immunogenicity. When oligosaccharides were conjugated through terminal aldehyde groups generated by deamination, modification of the exocyclic chain of sialic acid did not influence immunogenicity.
Cloning, Characterization, and Expression ofBartonella henselae p26
Authors: Werner Jonathan A. , Feng Sunlian , Kasten Rickie W. , Hodzic Emir , Chomel Bruno B. , Barthold Stephen W.
Published: August 2006

In order to identify immunoreactiveBartonella henselaeproteins,B. henselaeantiserum from an experimentally infected cat was used to screen aB. henselaegenomic DNA expression library. One immunoreactive phage clone contained a gene (p26) with significant nucleotide identity with orthologs in brucellae, bartonellae, and several plant-associated bacteria.p26gene sequences from fourB. henselaestrains, oneB. koehleraestrain, and oneB. clarridgeiaestrain were cloned. Comparative nucleotide sequence analysis showed thatp26is a potential marker for molecular diagnosis of infection, as well as for identification to species level and genotyping ofBartonellasp. isolates. Alignment of the predicted amino acid sequences illustrated conserved putative protein features including a hydrophobic transmembrane region, a peptide cleavage site, and four dominant antigenic sites. Expression ofp26inEscherichia coliproduced two proteins (26 and 27.5 kDa), both of which were reactive with feline anti-B. henselaeantisera. Furthermore, murine hyperimmune serum raised against either recombinant protein reacted with both proteins. No reactivity to either recombinant protein was detected in nonimmune serum, and reactivity persisted as long as 20 weeks for one cat. Thep26protein product is an immunodominant antigen that is expressed during infection in cats as a preprotein and is subsequently cleaved to form mature P26.
Anti-CD25 Antibody Treatment of Mice Vaccinated and Challenged withBorreliaspp. Does Not Exacerbate Arthritis but Inhibits Borreliacidal Antibody Production
Authors: Nardelli Dean T. , Warner Thomas F. , Callister Steven M. , Schell Ronald F.
Published: August 2006

CD4+CD25+T cells are a population of regulatory T cells responsible for the modulation of the immune response in several autoimmune and infectious disease models. We previously showed that adoptive transfer of enriched CD4+CD25+T cells also plays a major role in the prevention of arthritis inBorrelia-vaccinated (Borrelia burgdorferiisolate 297) and -challenged (B. bissettii) mice. Here, we present evidence that administration of anti-CD25 antibody at the time of challenge or at later intervals fails to enhance the development of severe destructive osteoarthropathy inBorrelia-vaccinated C57BL mice. However,Borrelia-vaccinated and -challenged mice receiving anti-CD25 antibody developed decreased borreliacidal antibody titers compared to vaccinated and challenged controls. These findings suggest that additional mechanisms besides CD4+CD25+T cells are involved in the regulation of the immune response toBorreliainfection following vaccination.
A Highly Sensitive and Subspecies-Specific Surface Antigen Enzyme- Linked Immunosorbent Assay for Diagnosis of Johne's Disease
Authors: Eda Shigetoshi , Bannantine John P. , Waters W. R. , Mori Yasuyuki , Whitlock Robert H. , Scott M. Cathy , Speer C. A.
Published: August 2006

Johne's disease (JD), or paratuberculosis, caused by
Mycobacterium avium
subsp.
paratuberculosis
, is one of the most widespread and economically important diseases of livestock and wild ruminants worldwide. Control of JD could be accomplished by diagnosis and good animal husbandry, but this is currently not feasible because commercially available diagnostic tests have low sensitivity levels and are incapable of diagnosing prepatent infections. In this study, a highly sensitive and subspecies-specific enzyme-linked immunosorbent assay was developed for the diagnosis of JD by using antigens extracted from the surface of
M. avium
subsp.
paratuberculosis
. Nine different chemicals and various intervals of agitation by vortex were evaluated for their ability to extract the surface antigens. Various quantities of surface antigens per well in a 96-well microtiter plate were also tested. The greatest differences in distinguishing between JD-positive and JD-negative serum samples by ethanol vortex enzyme-linked immunosorbent assay (EVELISA) were obtained with surface antigens dislodged from 50 μg/well of bacilli treated with 80% ethanol followed by a 30-second interval of agitation by vortex. The diagnostic specificity and sensitivity of the EVELISA were 97.4% and 100%, respectively. EVELISA plates that had been vacuum-sealed and then tested 7 weeks later (the longest interval tested) had diagnostic specificity and sensitivity rates of 96.9 and 100%, respectively. In a comparative study involving serum samples from 64 fecal culture-positive cattle, the EVELISA identified 96.6% of the low-level fecal shedders and 100% of the midlevel and high-level shedders, whereas the Biocor ELISA detected 13.7% of the low-level shedders, 25% of the mid-level shedders, and 96.2% of the high-level shedders. Thus, the EVELISA was substantially superior to the Biocor ELISA, especially in detecting low-level and midlevel shedders. The EVELISA may form the basis for a highly sensitive and subspecies-specific test for the diagnosis of JD.
Use of Immunoglobulin G Avidity To Determine the Course of Disease in Visceral and Post-Kala-Azar Dermal Leishmaniasis Patients
Authors: Singh Redhu Naresh , Dey Ayan , Balooni Veena , Singh Sarman
Published: August 2006

In the present study, anti-
Leishmania
immunoglobulin G (IgG) avidity was used to estimate the approximate time of disease manifestation. Significant differences (
P
< 0.0001) were found between the levels of anti-rKE-16 IgG avidity in leishmaniasis patients with recent and chronic diseases. More than 76% of patients with an illness duration of less than 6 months had avidity of less than 70%, 94% of patients had less than 80% avidity, and all (100%) patients with illness of more than 6 months had avidity values higher than 70%. The study showed that avidity could successfully be used to pinpoint the duration of leishmaniasis.
DNA Vaccine UsingMycobacterium bovisAg85B Antigen Induces Partial Protection against Experimental Infection in BALB/c Mice
Authors: Teixeira Francisco M. , Teixeira Henrique C. , Ferreira Ana Paula , Rodrigues Michele F. , Azevedo Vasco , Macedo Gilson C. , Oliveira Sergio C.
Published: August 2006

Bovine tuberculosis is a major cause of economic loss in countries where it is endemic, and in some countries, it may be a significant zoonotic disease problem. Therefore, new strategies for vaccine development are required, and among them, genetic immunization has potential value. The main goal of this study was to test theMycobacterium bovisAg85B gene as a DNA vaccine following challenge with anM. bovisvirulent strain (ATCC 19274). Groups of BALB/c mice (n= 10) were immunized four times intramuscularly with the pCI-Ag85B construct or the pCI vector alone as the control. High titers of total immunoglobulin G (IgG), IgG1, and IgG2a anti-Ag85B were measured in pCI-Ag85B immunized mice when compared to the pCI control group. Regarding cellular immunity, significant levels of gamma interferon (IFN-γ) (1,100 ± 157 pg/ml) and tumor necrosis factor alpha (650 ± 42 pg/ml) but not interleukin-4 were detected in splenocyte culture supernatants of pCI-Ag85B-vaccinated mice following stimulation with recombinant Ag85B. Further, the main source of IFN-γ is CD8+T cells, as demonstrated by intracellular cytokine staining. As far as protection, a significant reduction in bacterial load in spleens (P< 0.05) was detected in pCI-Ag85B-immunized mice compared to the pCI vector control group. The results obtained here suggest that use of the Ag85B DNA vaccine is a promising strategy to controlM. bovisinfection due to its ability to induce a Th1 type of immune response. However, protective efficacy needs to be improved, since partial protection was achieved in spleens but not in lungs of vaccinated mice.
Reduced Expression of Toll-Like Receptor 2 on Peripheral Monocytes in Patients with Chronic Hepatitis B
Authors: Riordan Stephen M. , Skinner Narelle , Kurtovic Jelica , Locarnini Stephen , Visvanathan Kumar
Published: August 2006

Persistent infection with hepatitis B virus (HBV) likely depends on viral inhibition of host defenses. We report that chronic hepatitis B e antigen-positive HBV infection is associated with a significant reduction in peripheral blood monocyte expression of Toll-like receptor 2, a key component of innate immunity, thereby providing a mechanism by which wild-type HBV may establish persistent infection.
UNIFIED DESCRIPTION OF EARLY UNIVERSE WITH VARIABLE GRAVITATIONAL AND COSMOLOGICAL "CONSTANTS"
Authors: SINGH C. P.
Published: August 2006

Einstein's field equations with variable gravitational and cosmological "constants" are considered in the presence of perfect fluid for a spatially homogeneous and isotropic universe. Exact solutions of the field equations are obtained by using the "gamma-law" equation of state p=(γ-1)ρ, where the adiabatic parameter γ, varies with cosmic time. The functional form of γ, which is assumed to be the function of scale factor R as proposed by Carvalho, is used to describe the early evolution of universe. A unified description of early universe is given in which an inflationary phase is followed by radiation-dominated phase. The various physical aspects of the models are also discussed.
THE ALGEBRA OF OBSERVABLES OF THE CLOSED BOSONIC STRING IN (1+3)-DIMENSIONAL MINKOWSKI SPACE: UPDATING THE STRUCTURAL ANALYSIS
Authors: POHLMEYER K.
Published: August 2006

The purpose of this letter is to inform about some results and observations which shed new light on the structure of the algebra of string observables both in the classical and quantum theories.
PLASMA INDUCED NEUTRINO RADIATIVE DECAY INSTEAD OF NEUTRINO SPIN LIGHT
Authors: KUZNETSOV A. V. , MIKHEEV N. V.
Published: August 2006

The conversion νL→νRγ* of a neutrino with a magnetic moment is considered, caused by the additional Wolfenstein energy acquired by a left-handed neutrino in medium, with an accurate account of the photon γ* dispersion in medium. It is shown that the threshold arises in the process, caused by the photon (plasmon) effective mass. This threshold leaves no room for the so-called "neutrino spin light" in the most of astrophysical situations.
QUARK–LEPTON SYMMETRY AND COMPLEMENTARITY
Authors: FALCONE D.
Published: August 2006

We argue that the difference between the observed approximate quark–lepton complementarity and the theoretical prediction based on realistic quark–lepton symmetry within the seesaw mechanism may be adjusted by means of a triplet contribution in the seesaw formula.
COMMON ORIGIN OF NEUTRINO MASS, DARK MATTER, AND BARYOGENESIS
Authors: MA ERNEST
Published: August 2006

Combining one established idea with two recent ones, it is pointed out for the first time that three of the outstanding problems of particle physics and cosmology, i.e. neutrino mass, dark matter, and baryogenesis, may have a simple common solution, arising from the interactions of a single term, with experimentally verifiable consequences.
AN ALGEBRAIC TOPOLOGICAL METHOD FOR FEATURE IDENTIFICATION
Authors: CARLSSON ERIK , CARLSSON GUNNAR , DE SILVA VIN
Published: August 2006

We develop a mathematical framework for describing local features of a geometric object—such as the edges of a square or the apex of a cone—in terms of algebraic topological invariants. The main tool is the construction of a "tangent complex" for an arbitrary geometrical object, generalising the usual tangent bundle of a manifold. This framework can be used to develop algorithms for automatic feature location. We give several examples of applying such algorithms to geometric objects represented by point-cloud data sets.
THE ANCHORED VORONOI DIAGRAM: STATIC, DYNAMIC VERSIONS AND APPLICATIONS
Authors: DÍAZ-BÁÑEZ J. M. , GÓMEZ F. , VENTURA I.
Published: August 2006

For a given set S of n points in the plane and a fixed point o, we introduce the Voronoi diagram of S anchored at o. It will be defined as an abstract Voronoi diagram that uses as bisectors the following curves. For each pair of points p, q in S, the bisecting curve between p and q is the locus of points x in the plane such that the line segment [Formula: see text] is equidistant to both p and q. We show that those bisectors have nice properties and, therefore, this new structure can be computed in O(n log n) time and O(n) space both for nearest-site and furthest-site versions. Also, we prove that the dynamic version of this diagram can be built in O(n2λ6s+2(n) log n) time complexity, where s is a constant depending on the function that describes the motion of the points. Finally, we show how to use these structures for solving several locational optimization problems.
THE TSP AND THE SUM OF ITS MARGINAL VALUES
Authors: DROR MOSHE , LEE YUSIN , ORLIN JAMES B. , POLISHCHUK VALENTIN
Published: August 2006

This paper introduces a new notion related to the traveling salesperson problem (TSP) — the notion of the TSP ratio. The TSP ratio of a TSP instance I is the sum of the marginal values of the nodes of I divided by the length of the optimal TSP tour on I, where the marginal value of a node i ∈ I is the difference between the length of the optimal tour on I and the length of the optimal tour on I\i. We consider the problem of establishing exact upper and lower bounds on the TSP ratio. To our knowledge, this problem has not been studied previously.

We present a number of cases for which the ratio is never greater than 1. We establish a tight upper bound of 2 on the TSP ratio of any metric TSP. For the TSP on six nodes, we determine the maximum ratio of 1.5 in general, 1.2 for the case of metric TSP, and 10/9 for the geometric TSP in the L1 metric. We also compute the TSP ratio experimentally for a large number of random TSP instances on small number of points.