bluuebunny/crossref_metadata_2025 huggingface dataset:
Drag Reduction of Tractor-Trailers Using Optimized Add-On Devices
Authors: Hsu Fu-Hung , Davis Roger L.
Published: August 2010

Tractor-trailers have a higher drag coefficient than other vehicles due to their bluff-body shape. Numerous add-on devices have been invented to help reduce drag and fuel consumption. The current research extends our previous idea of add-on humps and investigates their effect in conjunction with curved boat-tail flaps. Computational fluid dynamics in the form of unsteady Reynolds-averaged Navier–Stokes and detached-eddy simulations were used to determine viable design strategies. A 3D baseline computational model was constructed using an Ahmed body. Design optimization was applied on the new add-on devices. The results from the optimized design were shown to have a 50.9% reduction in drag coefficient.
Numerical Modeling and Analysis of Entrainment in Turbulent Jets After the End of Injection
Authors: Singh Satbir , Musculus Mark P. B.
Published: August 2010

Previous velocity and scalar measurements in both single-phase jets and two-phase diesel fuel sprays indicate that after the flow at the nozzle decelerates, ambient-gas entrainment increases compared to a steady jet. Previous studies using simplified analytical models and computational fluid dynamics (CFD) simulations using a one-dimensional (1D) inviscid, incompressible momentum equation have predicted that an “entrainment wave” propagates downstream along the jet axis during and after the deceleration, increasing entrainment by up to a factor of 3. In this study, entrainment is analyzed using the full compressible, unsteady Navier–Stokes momentum equations in axisymmetric two-dimensional (2D) CFD simulations of single-pulsed transient round gas jets. The 2D simulations confirm the existence of the entrainment wave, although the region of increased entrainment is distributed over a wider axial region of the jet than predicted by the simplified 1D model, so that the peak entrainment rate increases by only 50% rather than by a factor of 3. In the long time limit, both models show that the rate of mixing relative to the local injected fluid concentration increases significantly, approaching a factor of 3 or more increase in the wake of the entrainment wave (relative to a steady jet). Analysis of the terms in the momentum equation shows that the entrainment wave in the full 2D CFD predictions occurs in two phases. The entrainment first increases slightly due to a radial pressure gradient induced by a relatively fast acoustic wave, which the simple 1D model does not account for. The acoustic wave is followed by a slower momentum wave of decreased axial velocity initiated at the nozzle, which is convected downstream at the local flow velocities. The largest increase in entrainment accompanies the momentum wave, which is captured by the 1D momentum-equation model.
Student understanding of the direction of the magnetic force on a charged particle
Authors: Scaife Thomas M. , Heckler Andrew F.
Published: August 2010

We study student understanding of the direction of the magnetic force experienced by a charged particle moving through a homogeneous magnetic field in both the magnetic pole and field line representations of the magnetic field. In five studies, we administer a series of simple questions in either written or interview format. Our results indicate that although students begin at the same low level of performance in both representations, they answer correctly more often in the field line representation than in the pole representation after instruction. This difference is due in part to more students believing that charges are attracted to magnetic poles than believing that charges are pushed along magnetic field lines. Although traditional instruction is fairly effective in teaching students to answer correctly up to a few weeks following instruction, especially for the field line representation, some students revert to their initial misconceptions several months after instruction. The responses reveal persistent and largely random sign errors in the direction of the force. The sign errors are largely nonsystematic and due to confusion about the direction of the magnetic field and the execution and choice of the right-hand rule and lack of recognition of the noncommutativity of the cross product.
The Universe Online
Authors: Raddick M. Jordan , Szalay Alexander S.
Published: August 2010

Data from the Sloan Digital Sky Survey can be used by students, teachers, and the public to contribute to scientific research.
Secreted Peptide Signals Required for Maintenance of Root Stem Cell Niche in
Arabidopsis
Authors: Matsuzaki Yo , Ogawa-Ohnishi Mari , Mori Ayaka , Matsubayashi Yoshikatsu
Published: August 2010

Making Roots

A tiny bunch of stem cells generates the bulk and diversity of plant roots. These cells are found at the root meristem and are themselves regulated by signaling inputs from a variety of sources. In
Arabidopsis
,

Matsuzaki
et al.

(p.
1065
) have identified a family of peptide factors that regulate these root stem cells. These peptides, known as root meristem growth factors, carry the post-translational modification, tyrosine sulfation, and are essential for maintaining the root stem cell niche.
Opening the Door to Peptide-Based Porous Solids
Authors: Wright Paul A.
Published: August 2010

The twisting motion of a dipeptide linker group acts as a pressure-sensitive gate for the adsorption of gases within a crystalline solid.
New XMRV Paper Looks Good, Skeptics Admit—Yet Doubts Linger
Authors: Enserink Martin
Published: August 2010

This week, a long-awaited paper about the link between a virus and chronic fatigue syndrome (CFS) finally saw the light of day. The study confirms a controversial 2009 paper that reported CFS patients are often infected with the virus, called XMRV.
Hard Summer for Corals Kindles Fears for Survival of Reefs
Authors: Normile Dennis
Published: August 2010

Coral reefs are reeling from extensive bleaching in the Indian Ocean and throughout Southeast Asia. And although some hard-hit areas have cooled—offering hope that some reefs may rebound—other regions are just now heating up.
Astronomers Hope Their Prize Telescope Isn't Blinded by the Light
Authors: Stone Richard
Published: August 2010

Chinese astronomers thought they had their hands full, fine-tuning their complicated new survey telescope into next year. Now they have a more urgent problem: Light pollution could jeopardize its ambitious science program.
Organizers Panned for Omitting Israelis From Meeting in Jordan
Authors: Service Robert F.
Published: August 2010

Political tensions between Israel and the Arab world are threatening to overshadow an upcoming chemistry conference in Jordan. The verbal sparring has already created plenty of raw feelings and led to much finger-pointing.
NSF Turns Math Earmark on Its Ear to Fund New Institute
Authors: Mervis Jeffrey
Published: August 2010

The National Science Foundation has quietly folded a recent earmark into a competitive grants program, eliminating what seemed to be one state's advantage.
Google Earth Shows Clandestine Worlds
Authors: Pringle Heather
Published: August 2010

Archaeologists are using Google's eye in the sky to bring covert activities to light, from prison building at Guantánamo Bay to looting in the Middle East.
A Better Means of Modeling Data
Authors: Carlson Nichole
Published: August 2010

New approximations for Bayesian estimation make its use more computationally feasible.
Technical and Diagnostic Performance of Five Commercial Anti-Diphtheria Toxoid IgG Enzyme-Linked Immunosorbent Assay Kits
Authors: Faruq A. , Dadson L. , Cox H. , Alcock F. , Parker A. R.
Published: August 2010

The technical and diagnostic performances of five commercially available enzyme-linked immunosorbent assays for the measurement of anti-diphtheria toxoid IgG antibodies were evaluated. There was good agreement between the relative sensitivities of the five assays, but the relative specificity of one of the assays differed from that of the other four assays. Three of the five assays possessed recoveries of the international reference material NIBSC 00/496 within the range of 90% to 110% at antibody levels >0.1 IU/ml. The data suggest that there are manufacture-dependent differences in relative sensitivity, specificity, and accuracy for the determination of anti-diphtheria toxoid IgG antibodies that could result in different diagnostic interpretations.
Development of Human-Murine Chimeric Immunoglobulin G for Use in the Serological Detection of Human Flavivirus and Alphavirus Antibodies
Authors: Thibodeaux Brett A. , Panella Amanda N. , Roehrig John T.
Published: August 2010

Diagnosis of human arboviral infections relies heavily on serological techniques such as the immunoglobulin M (IgM) antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) and the indirect IgG ELISA. Broad application of these assays is hindered by the lack of standardized positive human control sera that react with a wide variety of flaviviruses (e.g., dengue, West Nile, yellow fever, Japanese encephalitis, Saint Louis encephalitis, and Powassan viruses), or alphaviruses (e.g., Eastern equine encephalitis, Western equine encephalitis, Venezuelan equine encephalitis, and chikungunya viruses) that can cause human disease. We have created human-murine chimeric monoclonal antibodies (cMAbs) by combining the variable regions of flavivirus (6B6C-1) or alphavirus (1A4B-6) broadly cross-reactive murine MAbs (mMAbs) with the constant region of human IgG1. These cMAbs may be used as standardized reagents capable of replacing human infection-immune-positive control sera in indirect IgG ELISA for diagnosis of all human flaviviral or alphaviral infections. The IgG cMAbs secreted from plasmid-transformed Sp2/0-Ag14 cells had serological activity identical to that of the parent mMAbs, as measured by ELISA using multiple flaviviruses or alphaviruses.
Immunogenicity of an AutogenousStreptococcus suisBacterin in Preparturient Sows and Their Piglets in Relation to Protection after Weaning
Authors: Baums Christoph Georg , Brüggemann Christian , Kock Christoph , Beineke Andreas , Waldmann Karl-Heinz , Valentin-Weigand Peter
Published: August 2010

Streptococcus suisis an important porcine pathogen causing meningitis and other invasive diseases in piglets of different ages. Application ofS. suisserotype 2 bacterins to specific-pathogen-free (SPF) weaning piglets has been demonstrated to protect against the homologous serotype. However, autogenousS. suisbacterins are also applied to sows and suckling piglets in the field. Therefore, comparative evaluation of different bacterin immunization regimes, including sow vaccination, was performed in this study. The main objectives were to determine the immunogenicity of anS. suisbacterin in sows prepartum and its influence on active immunization of piglets. Experimental infection of 6- and 8-week-old weaning piglets was performed to elucidate protective efficacies. Humoral immune responses were investigated by an enzyme-linked immunosorbent assay (ELISA) measuring muramidase-released protein (MRP)-specific IgG titers and by opsonophagocytosis assays. Bacterin application elicited high MRP-specific IgG titers in the serum and colostrum of sows, as well as opsonizing antibodies. Piglets from vaccinated sows had significantly higher MRP-specific titers than respective piglets from nonvaccinated sows until 6 weeks postpartum. Vaccination of suckling piglets did not result in high MRP-specific titers nor in induction of opsonizing antibodies. Furthermore, neither vaccination of suckling nor of weaning piglets from immunized sows was associated with a prominent active immune response and protection at 8 weeks postpartum. However, protection was observed in respective 6-week-old weaning piglets, most likely because of protective maternal immunity. In conclusion, this study provides the first results suggesting protective passive maternal immunity forS. suisserotype 2 after bacterin vaccination of sows and a strong inhibitory effect on active immunization of suckling and weaning piglets, leading to highly susceptible growers.
Improved Diagnosis of
Strongyloides stercoralis
Using Recombinant Antigen-Based Serologies in a Community-Wide Study in Northern Argentina
Authors: Krolewiecki Alejandro J. , Ramanathan Roshan , Fink Valeria , McAuliffe Isabel , Cajal Silvana P. , Won Kimberly , Juarez Marisa , Di Paolo Adriana , Tapia Laura , Acosta Norma , Lee Rogan , Lammie Patrick , Abraham David , Nutman Thomas B.
Published: August 2010

The serodiagnosis of
Strongyloides stercoralis
infection by enzyme-linked immunosorbent assays based on crude antigen (CrAg-ELISA), while useful, has been limited by the reliance on crude parasite extracts. Newer techniques such as the luciferase immunoprecipitation system assay (LIPS), based on a 31-kDa recombinant antigen (termed NIE) from
S. stercoralis
and/or the recombinant antigen
S. stercoralis
immunoreactive antigen (SsIR), or the NIE-ELISA have shown promise in controlled settings. We compared each of these serologic assays in individuals from both regions of the world in which
S. stercoralis
is endemic and those in which it is not. A comprehensive stool evaluation (sedimentation concentration, Baermann concentration with charcoal cultures, agar plate, and Harada-Mori) and four different serologic techniques using CrAg-ELISA or recombinant NIE-ELISA as well as LIPS using NIE alone or in combination with a second recombinant antigen (NIE/SsIR-LIPS) were compared among individuals with parasitologically proven infection (
n
= 251) and healthy controls from regions of the world in which the infection is nonendemic (
n
= 11). Accuracy was calculated for each assay. The prevalence of
S. stercoralis
infection was 29.4% among Argentinean stool samples (
n
= 228). Sedimentation concentration and Baermann were the most sensitive stool-based methods. NIE-LIPS showed the highest sensitivity (97.8%) and specificity (100%) of the serologic assays. The calculated negative predictive value was highest for both the NIE-LIPS and CrAg-ELISA (>97%) irrespective of disease prevalence. No cross-reactivity with soil-transmitted helminths was noted. NIE-LIPS compares favorably against the current CrAg-ELISA and stool evaluation, providing additional accuracy and ease of performance in the serodiagnosis of
S. stercoralis
infections irrespective of disease prevalence.
Detection of Hepatitis B and C Viruses in Almost All Hepatocytes by Modified PCR-BasedIn SituHybridization
Authors: Nuriya Hideko , Inoue Kazuaki , Tanaka Takeshi , Hayashi Yukiko , Hishima Tsunekazu , Funata Nobuaki , Kaji Kyosuke , Hayashi Seishu , Kaneko Shuichi , Kohara Michinori
Published: August 2010

Although PCR-basedin situhybridization (PCR-ISH) can be used to determine the distribution and localization of pathogens in tissues, this approach is hampered by its low specificity. Therefore, we used a highly specific and sensitive PCR-ISH method to reveal the lobular distribution and intracellular localization of hepatitis B virus (HBV) and HCV in chronic liver disease and to clarify the state of persistent HBV and HCV infection in the liver. HBV genomic DNA was detected in almost all hepatocytes, whereas HBV RNA or protein was differentially distributed only in a subset of the HBV DNA-positive region. Further, HCV genomic RNA was detected in almost all hepatocytes and was localized to the cytoplasm. HCV RNA was also detected in the epithelium of the large bile duct but not in endothelial cells, portal tracts, or sinusoidal lymphocytes. In patients with HBV and HCV coinfection, HCV RNA was localized to the noncancerous tissue, whereas HBV DNA was found only in the cancerous tissue. Using this novel PCR-ISH method, we could visualize the staining pattern of HBV and HCV in liver sections, and we obtained results consistent with those of real-time detection (RTD)-PCR analysis. In conclusion, almost all hepatocytes are infected with HBV or HCV in chronic liver disease; this finding implies that the viruses spreads throughout the liver in the chronic stage.
Rapid Detection of Respiratory Tract Viral Infections and Coinfections in Patients with Influenza-Like Illnesses by Use of Reverse Transcription-PCR DNA Microarray Systems
Authors: Renois Fanny , Talmud Déborah , Huguenin Antoine , Moutte Lauryane , Strady Christophe , Cousson Joel , Lévêque Nicolas , Andréoletti Laurent
Published: August 2010

We prospectively tested 95 nasal swabs or nasopharyngeal aspirates taken from 56 adults and 39 children visiting the Reims University Medical Centre (northern France) for influenza-like illnesses (ILI) during the early stage of the French influenza A/H1N1v pandemic (October 2009). Respiratory samples were tested using a combination of two commercially available reverse transcription-PCR (RT-PCR) DNA microarray systems allowing rapid detection of influenza A virus strains, including the new A/H1N1v strain as well as 20 other common or newly discovered respiratory viruses. Concomitantly, a generic and classical real-time RT-PCR assay was performed to detect all circulating influenza A virus strains in the same samples. Of the 95 respiratory samples tested, 30 (31%) were positive for the detection of influenza A/H1N1v virus infection by both RT-PCR DNA microarray and classical real-time RT-PCR detection assays. Among the infections, 25 (83%) were monoinfections, whereas 5 (17%) were multiple infections associating influenza A/H1N1v virus with coronavirus (CoV), human bocavirus (HBoV), respiratory syncytial virus (RSV), or human rhinoviruses (HRVs). Of the 95 respiratory samples tested, 35 (37%) were positive for respiratory viruses other than influenza A/H1N1v virus. Among these infections, we observed 30 monoinfections (HRVs [63%], parainfluenza viruses [PIVs] [20%]), influenza A/H3N2 virus [6%], coronavirus [4%], and HBoV [4%]) and 5 multiple infections, in which HRVs and PIVs were the most frequently detected viruses. No specific single or mixed viral infections appeared to be associated significantly with secondary hospitalization in infectious disease or intensive care departments during the study period (
P
> 0.5). The use of RT-PCR DNA microarray systems in clinical virology practice allows the rapid and accurate detection of conventional and newly discovered viral respiratory pathogens in patients suffering from ILI and therefore could be of major interest for development of new epidemiological survey systems for respiratory viral infections.
Propionibacterium acnes
and
Staphylococcus epidermidis
Isolated from Refractory Endodontic Lesions Are Opportunistic Pathogens
Authors: Niazi Sadia A. , Clarke Douglas , Do Thuy , Gilbert Steven C. , Mannocci Francesco , Beighton David
Published: August 2010

The predominant cultivable microbiota from 20 refractory endodontic lesions (9 with abscesses and 11 without abscesses) were determined, and
Propionibacterium acnes
and
Staphylococcus epidermidis
were among the most predominant organisms. The number of species identified from lesions with abscesses (14.1 ± 2.6) was significantly greater (
P
< 0.001) than the number from lesions without abscesses (7.4 ± 5.9). Comparison of perioral isolates using repetitive extragenic palindromic PCR of the same species from the same subjects demonstrated that the endodontic and skin populations were significantly different. The
P. acnes
isolates were typed on the basis of
recA
gene sequence comparison, and only three types (types I, II, and III) were identified among 125 isolates examined. However, we found that type I (type IA and IB) isolates were primarily isolated from the skin, while types II and III were significantly more likely to be isolated from the endodontic lesions (
P
< 10
−10
). We found that the robustness of the
recA
phylotypes was not strong by comparing the partial gene sequences of six putative virulence determinants, PAmce, PAp60, PA-25957, PA-5541, PA-21293, and PA-4687. The resulting neighbor-joining trees were incongruent, and significant (phi test;
P
= 2.2 × 10
−7
) evidence of recombination was demonstrated, with significant phylogenetic heterogeneity being apparent within the clusters.
P. acnes
and
S. epidermidis
isolated from refractory endodontic infections, with or without periapical abscesses, are likely to be nosocomial infections.
Herbaspirillum
Species Bacteremia in a Pediatric Oncology Patient
Authors: Ziga Edward D. , Druley Todd , Carey-Ann Burnham D.
Published: August 2010

Herbaspirillum
species, an organism commonly found in soil, has only recently been linked to disease in humans. We report
Herbaspirillum
bacteremia in a 2-year-old female patient following a hematopoietic stem cell transplant for relapsed acute lymphoblastic leukemia.
Characterization of Vancomycin-Resistant
Enterococcus faecium
Isolated from Swine in Three Michigan Counties
Authors: Donabedian Susan M. , Perri Mary Beth , Abdujamilova Nodira , Gordoncillo Mary Joy , Naqvi Amir , Reyes Katherine C. , Zervos Marcus J. , Bartlett Paul
Published: August 2010

Vancomycin-resistant enterococci are a major cause of nosocomial infections but are rarely found in humans in the community and have not been identified in food animals in the United States. We evaluated a total of 360 fecal specimens from humans and their animals being raised for exhibit at three county fairs in Michigan. Fecal samples from 158 humans, 55 swine, 50 cattle, 25 horses, 57 sheep, 14 goats, and 1 llama were obtained and plated onto Enterococcosel agar containing 16 μg/ml of vancomycin. Vancomycin-resistant
Enterococcus faecium
(VREF) was isolated from six pigs but not from humans or any animal other than pigs. All six VREF isolates had a MIC to vancomycin of ≥256 μg/ml and contained the
vanA
gene. Pulsed-field gel electrophoresis (PFGE) patterns of the six VREF isolates were ≥80% similar. Multilocus sequence typing (MLST) revealed sequence type 5 (ST5) (
n
= 2), ST6 (
n
= 3), and ST185 (
n
= 1), which are
E. faecium
sequence types belonging to clonal complex 5 (CC5). These findings show the dissemination of VREF strains among pigs in three Michigan counties. This is the first report of VRE found in food animals in the United States.
Compromised Spindle Assembly Checkpoint due to Altered Expression of Ubch10 and Cdc20 in Human Papillomavirus Type 16 E6- and E7-Expressing Keratinocytes
Authors: Patel Daksha , McCance Dennis J.
Published: August 2010

Cells expressing human papillomavirus type 16 (HPV-16) E6 and E7 proteins exhibit deregulation of G
2
/M genes, allowing bypass of DNA damage arrest signals. Normally, cells with DNA damage that override the G
2
damage checkpoint would precociously enter mitosis and ultimately face mitotic catastrophe and apoptotic cell death. However, E6/E7-expressing cells (E6/E7 cells) have the ability to enter and exit mitosis in the presence of DNA damage and continue with the next round of the cell cycle. Little is known about the mechanism that allows these cells to gain entry into and exit from mitosis. Here, we show that in the presence of DNA damage, E6/E7 cells have elevated levels of cyclin B, which would allow entry into mitosis. Also, as required for exit from mitosis, cyclin B is degraded in these cells, permitting initiation of the next round of DNA synthesis and cell cycle progression. Proteasomal degradation of cyclin B by anaphase-promoting complex/cyclosome (APC/C) is, in part, due to elevated levels of the E2-conjugating enzyme, Ubch10, and the substrate recognition protein, Cdc20, of APC/C. Also, in E6/E7 cells with DNA damage, while Cdc20 is complexed with BubR1, indicating an active checkpoint, it is also present in complexes free of BubR1, presumably allowing APC/C activity and slippage through the checkpoint.
Environmental Sources of Scrapie Prions
Authors: Maddison Ben C. , Baker Claire A. , Terry Linda A. , Bellworthy Susan J. , Thorne Leigh , Rees Helen C. , Gough Kevin C.
Published: August 2010

Ovine scrapie and cervine chronic wasting disease show considerable horizontal transmission. Here we report that a scrapie-affected sheep farm has a widespread environmental contamination with prions. Prions were amplified by protein-misfolding cyclic amplification (sPMCA) from seven of nine environmental swab samples taken, including those from metal, plastic, and wooden surfaces. Sheep had been removed from the areas from which the swabs were taken up to 20 days prior to sampling, indicating that prions persist for at least that long. These data implicate inanimate objects as environmental reservoirs for prion infectivity that are likely to contribute to facile disease transmission.
Human Cytomegalovirus Induces the Endoplasmic Reticulum Chaperone BiP through Increased Transcription and Activation of Translation by Using the BiP Internal Ribosome Entry Site
Authors: Buchkovich Nicholas J. , Yu Yongjun , Pierciey Francis J. , Alwine James C.
Published: August 2010

The endoplasmic reticulum (ER) chaperone BiP (immunoglobulin binding protein) plays a major role in the control of the unfolded protein response. We have previously shown that BiP levels are dramatically increased during human cytomegalovirus (HCMV) infection, where BiP performs unique roles in viral assembly and egress. We show that BiP mRNA levels increase during infection due to activation of the BiP promoter by the major immediate-early (MIE) proteins. The BiP promoter, like other ER stress-activated promoters, contains endoplasmic reticulum stress elements (ERSEs), which are activated by unfolded protein response (UPR)-induced transcription factors. However, these elements are not needed for MIE protein-mediated transcriptional activation; thus, a virus-specific transcriptional activation mechanism is used. Transcriptional activation results in only a 3- to 4-fold increase in BiP mRNA, suggesting that additional mechanisms for BiP production are utilized. The BiP mRNA contains an internal ribosome entry site (IRES) which increases the level of BiP mRNA translation. We show that utilization of the BiP IRES is dramatically increased in HCMV-infected cells. Utilization of the BiP IRES can be activated by the La autoantigen, also called Sjögren's syndrome antigen B (SSB). We show that SSB/La levels are significantly increased during HCMV infection, and SSB/La depletion causes the loss of BiP IRES utilization and lowers endogenous BiP levels in infected cells. Our data show that BiP levels increase in HCMV-infected cells through the combination of increased BiP gene transcription mediated by the MIE proteins and increased BiP mRNA translation due to SSB/La-induced utilization of the BiP IRES.
Oseltamivir-Resistant Variants of the 2009 Pandemic H1N1 Influenza A Virus Are Not Attenuated in the Guinea Pig and Ferret Transmission Models
Authors: Seibert Christopher W. , Kaminski Michael , Philipp Jennifer , Rubbenstroth Dennis , Albrecht Randy A. , Schwalm Folker , Stertz Silke , Medina Rafael A. , Kochs Georg , García-Sastre Adolfo , Staeheli Peter , Palese Peter
Published: August 2010

Oseltamivir is routinely used worldwide for the treatment of severe influenza A virus infection, and should drug-resistant pandemic 2009 H1N1 viruses become widespread, this potent defense strategy might fail. Oseltamivir-resistant variants of the pandemic 2009 H1N1 influenza A virus have been detected in a substantial number of patients, but to date, the mutant viruses have not moved into circulation in the general population. It is not known whether the resistance mutations in viral neuraminidase (NA) reduce viral fitness. We addressed this question by studying transmission of oseltamivir-resistant mutants derived from two different isolates of the pandemic H1N1 virus in both the guinea pig and ferret transmission models.
In vitro
, the virus readily acquired a single histidine-to-tyrosine mutation at position 275 (H275Y) in viral neuraminidase when serially passaged in cell culture with increasing concentrations of oseltamivir. This mutation conferred a high degree of resistance to oseltamivir but not zanamivir. Unexpectedly, in guinea pigs and ferrets, the fitness of viruses with the H275Y point mutation was not detectably impaired, and both wild-type and mutant viruses were transmitted equally well from animals that were initially inoculated with 1:1 virus mixtures to naïve contacts. In contrast, a reassortant virus containing an oseltamivir-resistant seasonal NA in the pandemic H1N1 background showed decreased transmission efficiency and fitness in the guinea pig model. Our data suggest that the currently circulating pandemic 2009 H1N1 virus has a high potential to acquire drug resistance without losing fitness.
Murine Coronavirus Receptors Are Differentially Expressed in the Central Nervous System and Play Virus Strain-Dependent Roles in Neuronal Spread
Authors: Bender Susan J. , Phillips Judith M. , Scott Erin P. , Weiss Susan R.
Published: August 2010

Coronavirus infection of the murine central nervous system (CNS) provides a model for studies of viral encephalitis and demyelinating disease. Mouse hepatitis virus (MHV) neurotropism varies by strain: MHV-A59 causes mild encephalomyelitis and demyelination, while the highly neurovirulent strain JHM.SD (MHV-4) causes fatal encephalitis with extensive neuronal spread of virus. In addition, while neurons are the predominant CNS cell type infectedin vivo, the canonical receptor for MHV, the carcinoembryonic antigen family member CEACAM1a, has been demonstrated only on endothelial cells and microglia. In order to investigate whether CEACAM1a is also expressed in other cell types,ceacam1amRNA expression was quantified in murine tissues and primary cells. As expected, among CNS cell types, microglia expressed the highest levels ofceacam1a, but lower levels were also detected in oligodendrocytes, astrocytes, and neurons. Given the low levels of neuronal expression ofceacam1a, primary neurons from wild-type andceacam1aknockout mice were inoculated with MHV to determine the extent to which CEACAM1a-independent infection might contribute to CNS infection. While both A59 and JHM.SD infected small numbers ofceacam1aknockout neurons, only JHM.SD spread efficiently to adjacent cells in the absence of CEACAM1a. Quantification of mRNA for theceacam1a-related genesceacam2andpsg16(bCEA), which encode proposed alternative MHV receptors, revealed lowceacam2expression in microglia and oligodendrocytes andpsg16expression exclusively in neurons; however, only CEACAM2 mediated infection in human 293T cells. Therefore, neither CEACAM2 nor PSG16 is likely to be an MHV receptor on neurons, and the mechanism for CEACAM1a-independent neuronal spread of JHM.SD remains unknown.
Economical Evolution: Microbes Reduce the Synthetic Cost of Extracellular Proteins
Authors: Smith Daniel R. , Chapman Matthew R.
Published: August 2010

Protein evolution is not simply a race toward improved function. Because organisms compete for limited resources, fitness is also affected by the relative economy of an organism’s proteome. Indeed, many abundant proteins contain relatively high percentages of amino acids that are metabolically less taxing for the cell to make, thus reducing cellular cost. However, not all abundant proteins are economical, and many economical proteins are not particularly abundant. Here we examined protein composition and found that the relative synthetic cost of amino acids constrains the composition of microbial extracellular proteins. In
Escherichia coli
, extracellular proteins contain, on average, fewer energetically expensive amino acids independent of their abundance, length, function, or structure. Economic pressures have strategically shaped the amino acid composition of multicomponent surface appendages, such as flagella, curli, and type I pili, and extracellular enzymes, including type III effector proteins and secreted serine proteases. Furthermore,
in silico
analysis of
Pseudomonas syringae
,
Mycobacterium tuberculosis
,
Saccharomyces cerevisiae
, and over 25 other microbes spanning a wide range of GC content revealed a broad bias toward more economical amino acids in extracellular proteins. The synthesis of any protein, especially those rich in expensive aromatic amino acids, represents a significant investment. Because extracellular proteins are lost to the environment and not recycled like other cellular proteins, they present a greater burden on the cell, as their amino acids cannot be reutilized during translation. We hypothesize that evolution has optimized extracellular proteins to reduce their synthetic burden on the cell.

IMPORTANCE
Microbes secrete proteins to perform essential interactions with their environment, such as motility, pathogenesis, biofilm formation, and resource acquisition. However, because microbes generally lack protein import systems, secretion is often a one-way street. Consequently, secreted proteins are less likely to be recycled by the cell due to environmental loss. We demonstrate that evolution has in turn selected these extracellular proteins for increased economy at the level of their amino acid composition. Compared to their cellular counterparts, extracellular proteins have fewer synthetically expensive amino acids and more inexpensive amino acids. The resulting bias lessens the loss of cellular resources due to secretion. Furthermore, this economical bias was observed regardless of the abundance, length, structure, or function of extracellular proteins. Thus, it appears that economy may address the compositional bias seen in many extracellular proteins and deliver further insight into the forces driving their evolution.
Return-to-work interventions integrated into cancer care: a systematic review
Authors: Tamminga S J , de Boer A G E M , Verbeek J H A M , Frings-Dresen M H W
Published: August 2010

Objectives

The purpose of this study was to review the literature on the content of interventions focusing on return to work, employment status, or work retention in patients with cancer. Furthermore, the effect of the interventions on return to work was assessed in studies reporting return to work.

Methods

A literature search was conducted using the databases MEDLINE, PsycINFO, EMBASE and CINAHL. Articles that described a work-directed intervention focusing on return to work, employment status, or work retention in patients with cancer were included. The content of the work-directed part of the interventions was assessed based on two criteria for content analysis: 1. does the setting fit the shared care model of cancer survivor care? 2. Does the intervention target work ability and physical workload? For studies reporting return-to-work outcomes, the return-to-work rates were assessed. For studies that used a control group the ORs and the 95% CIs were calculated.

Results

Twenty-three articles describing 19 interventions met the inclusion criteria. Seven studies reported return-to-work outcomes of which four used a control group. Only three interventions aimed primarily at enhancing return to work or employment status. The most frequently reported work-directed components were encouragement, education or advice about work or work-related subjects (68%), vocational or occupational training (21%), or work accommodations (11%). One intervention fit the shared care model of cancer survivor care and five interventions enhanced work ability or decreased physical workload. The rate of return to work ranged from 37% to 89%. In one of the four controlled studies the intervention increased return to work significantly and in the other studies the results were insignificant.

Conclusions

Only few interventions are primarily aimed at enhancing return to work in patients with cancer and most do not fit the shared care model involving integrated cancer care. Future studies should be developed with well-structured work-directed components that should be evaluated in randomised controlled trials.
Connecting world youth with tobacco brands: YouTube and the internet policy vacuum on Web 2.0
Authors: Elkin Lucy , Thomson George , Wilson Nick
Published: August 2010

Background

The internet is an ideal forum for tobacco marketing, as it is largely unregulated and there is no global governing body for controlling content. Nevertheless, tobacco companies deny advertising on the internet.

Objective

To assess the extent and nature of English language videos available on the Web 2.0 domain ‘YouTube’ that contain tobacco brand images or words.

Methods

The authors conducted a YouTube search using five leading non-Chinese cigarette brands worldwide. The themes and content of up to 40 of the most viewed videos returned for each search were analysed: a total of 163 videos.

Results

A majority of the 163 tobacco brand-related videos analysed (71.2%, 95% CI 63.9 to 77.7) had pro-tobacco content, versus a small minority (3.7%) having anti-tobacco content (95% CI 1.4 to 7.8). Most of these videos contained tobacco brand content (70.6%), the brand name in the title (71.2%) or smoking imagery content (50.9%). One pro-smoking music video had been viewed over 2 million times. The four most prominent themes of the videos were celebrity/movies, sports, music and ‘archive’, the first three of which represent themes of interest to a youth audience.

Conclusions

Pro-tobacco videos have a significant presence on YouTube, consistent with indirect marketing activity by tobacco companies or their proxies. Since content may be removed from YouTube if it is found to breach copyright or if it contains offensive material, there is scope for the public and health organisations to request the removal of pro-tobacco content containing copyright or offensive material. Governments should also consider implementing Framework Convention on Tobacco Control requirements on the internet, to further reduce such pro-tobacco content.
Synergistic effects of a cellulase-producing Micromonospora carbonacea and an antibiotic-producing Streptomyces violascens on the suppression of Phytophthora cinnamomi root rot of Banksia grandis
Authors: El-Tarabily Khaled A. , Sykes Melissa L. , Kurtböke Ipek D. , Hardy Giles E. St. J. , Barbosa Aneli M. , Dekker Robert F. H.
Published: August 2010

Three polyvalent Streptomyces phages were used to isolate four Micromonospora species (M. carbonacea, M. chalcea, M. purpureochromogenes, and M. inositola) from mine-site rhizosphere soils in Western Australia. Streptomyces violascens was isolated using selective isolation techniques from the same soils. The Micromonspora spp. were examined for their ability to produce cellulases. Micromonospora carbonacea, M. chalcea, and M. purpureochromogenes, which were found to produce the enzyme, caused lysis of Phytophthora cinnamomi hyphae. Glasshouse trials showed that the use of the cellulase-producing M. carbonacea isolate, in conjunction with the antibiotic-producing S. violascens isolate, had a synergistic effect on the suppression of the Phytophthora root rot and in promoting growth of Banksia grandis. The importance of using a number of antagonists with different antagonistic abilities to control plant pathogenic fungi is discussed. Keywords: biological control, Micromonospora carbonacea, Streptomyces violascens, cellulases, Phytophthora cinnamomi.
THE EFFECTIVE STRESS RESPONSE OF A SATURATED CLAY SOIL TO REPEATED LOADING
Authors: Sangrey D. A. , Henkel D. J. , Esrig M. I.
Published: August 2010

The results of a series of tests designed to examine the behavior of saturated clay soil under repeated loading are reported. Triaxial tests, under conditions of axial symmetry, were used and the rates of deformation were chosen so as to permit the accurate measurement of pore water pressure at all stages of the tests.It was found that, for any particular consolidation history, a critical level of repeated stress existed. Below this critical level, a state of nonfailure equilibrium was reached in which the stress-strain curves followed closed hysteresis loops. Above the critical level of repeated stress, effective stress failure occurred; and each cycle of loading produced cumulative increases in deformation.An interesting feature of the test results was that a linear relationship between the magnitude of the applied repeated stress and the increase in pore water pressure was found for stress levels below the critical value.
VERTICAL MOVEMENTS AND CRACK-WIDTH CHANGES ON HIGHWAY PAVEMENT SURFACES
Authors: Rix H. H.
Published: August 2010

The results of periodic pavement elevation and crack-width measurements taken over a period of three to four years are presented. Both surface elevation and crack-width changes are shown to follow a similar seasonal cycle. Results show that the sub-grades studied were frozen as closed systems. It is shown that with closed system subgrade freezing the resulting vertical displacement of the pavement may be either positive or negative depending on the moisture content of the subgrade. The negative case, corresponding to vertical freezing shrinkage, occurred with dry clay subgrades. For a given observation section, seasonal surface movements in a vertical direction are shown to vary from the traffic lanes to the shoulders. The difference is explained in terms of corresponding differences in the subgrade moisture conditions.Results are presented which indicate that seasonal changes in the width of transverse pavement cracks cannot be fully explained in terms of simple thermal expansion and contraction in the asphaltic concrete pavement. Indirect evidence is presented which suggests that horizontal freezing shrinkage in a subgrade contributes to the seasonal cycle of crack-width changes.
HIGH-PRESSURE PHASE TRANSITION AND STABILITY OF CeSb, LaSb, AND LuSb WITH NaCl-TYPE STRUCTURE
Authors: SINGH SADHNA , SINGH R. K. , GOUR ATUL
Published: August 2010

We have predicted the phase transition pressures and corresponding relative volume changes of CeSb , LaSb , and LuSb having NaCl -type structure under high pressure using three-body interaction potential approach (TBIPA) incorporated with short-range van der Walls (vdW) interaction and zero point energy effects. We have obtained phase transition pressures and relative volume changes which are in close agreement with measured values. Thus TBIPA with vdW interaction and zero point energy effects are found to be promising potential models for the prediction of transition pressure and stability of rare-earth compounds.
QUANTUM THEORY OF RADIATION IN LASER PLASMA
Authors: LI WEI , LIU SHIBING , YU CHENGXIN , YANG WEI
Published: August 2010

Based on the Langevin noise approach, a full quantum theory of radiation in laser plasma is explored, where the laser intensity is limited to the range of 1010 W/cm2 to 1012 W/cm2 and the plasma is considered as a homogeneous dielectric background. By numerical calculation, the results show that the radiation is generated from the resonance of the plasma and the emitted rate of photons depends on the angular relation between the directions of radiation fields and the motion of the unbounded free electrons. In addition, the photons are more easily created under the lower collision frequency.
NU-PROCESS IN EXOTIC MODELS
Authors: PAULUCCI L. , HORVATH J. E.
Published: August 2010

The exact physical conditions generating the abundances of r-elements in environments such as supernovae explosions are still under debate. We evaluated the characteristics expected for the neutrino wind in the proposed model of type-II supernova driven by conversion of nuclear matter to strange matter. Neutrinos will change the final abundance of elements after freeze out of r-process nucleosynthesis, specially those close to mass peaks.
MODELING THE GRAVITATIONAL RECOIL IN THE M 83 CENTER
Authors: FERRARI G. G. , DOTTORI H.
Published: August 2010

Redshift determinations indicate that the radio-quasar J133658.3-295105 is in the nearby universe and not at z ≥ 1 as previously hypothesized. We propose that J133658.3-295105 is produced by the recoil of a black hole (BH) that results from the merger of two or three super massive BHs at the optical nucleus of NGC 5236 (M 83). We analyzed different merging scenarios by means of numerical simulations of binary and triple BH collisions using a third-order post-Newtonian approximation. We show that a merger of 3 BHs is more likely than that of 2 BHs to reproduce the simultaneous kick-off of J133658.3-295105 and the offset of the optical nucleus with respect to the galaxy kinematic center.
NON-GAUSSIANITY IN THE HILC FOREGROUND-REDUCED THREE-YEAR WMAP CMB MAP
Authors: BERNUI A. , REBOUÇAS M. J.
Published: August 2010

The detection or non-detection of primordial non-Gaussianity in the CMB data is essential not only to test alternative models of the physics of the early universe but also to discriminate among classes of inflationary models. Given this far-reaching consequences of such a non-Gaussianity detection for our understanding of the physics of the early universe, it is important to employ alternative indicators in order to have further information about the Gaussianity features of CMB that may be helpful for identifying their origins. In this way, a considerable effort has recently gone into the design of non-Gaussianity indicators, and in their application in the search for deviation from Gaussianity in the CMB data. Recently we have proposed two new large-angle non-Gaussianity indicators which provide measures of the departure from Gaussianity on large angular scales. We have used these indicators to carry out analyses of Gaussianity of the single frequency bands and of the available foreground-reduced five-year maps with and without the KQ75 mask. Here we extend and complement these studies by performing a new analysis of deviation from Gaussianity of the three-year harmonic ILC (HILC) foreground-reduced full-sky and KQ75 masked maps obtained from WMAP data. We show that these full-sky foreground-reduced maps present a significant deviation from Gaussianity, which is brought down to a level of consistency with Gaussianity when the KQ75 mask is employed.
THE EFFECT OF CONFINEMENT ON THE CFL QUARK PAIRING IN THE CHROMODIELECTRIC MODEL
Authors: DE CARVALHO S. M. , MALHEIRO M. , FREDERICO T. , CARLSON B. V. , FIOLHAIS M. , SCOCCOLA N. , GRUNFELD A. G.
Published: August 2010

An effective Lagrangian for quark pairing in nonlinear chromodielectric models (CDM) is derived in the leading order. The effective pairing coupling depends explicitly on the confinement field, χ, of the CDM manifesting a confinement effect on color superconductivity. The self-consistent gap equations are constructed and solved for the color-flavor locked phase. The pairing coupling, for the quartic χ potential used in the calculations, is inversely proportional to the second power of the χ field and to the χ mass squared. In the chiral solution the quarks do not pair, but in the chiral breaking solution, where χ is small and the effective pairing interaction is stronger, it does show pairing. Our results indicate that the vector channel of the gap is weaker than the scalar one.
AN INTEGRATED HYDRO AND BOLTZMANN APPROACH TO HEAVY ION REACTIONS
Authors: STEINHEIMER J. , NAHRGANG M. , PETERSEN H. , BLEICHER M.
Published: August 2010

Results on bulk particle observables, from a hybrid approach to relativistic heavy-ion collisions, are presented over a wide range of beam energies from E lab = 2 - 160 A GeV . In this model a hydrodynamic phase is integrated into a hadronic transport model. This setup enables us to study the effect of the equation of state of hot and dense nuclear matter on different observables from heavy-ion collider experiments. In addition we present a study on density fluctuations at a phase transition in the framework of chiral fluid dynamics.
SKYRME MODELS AND NUCLEAR MATTER PROPERTIES
Authors: DUTRA M. , LOURENÇO O. , DELFINO A. , SÁ MARTINS J. S.
Published: August 2010

In this preliminary study we select a set of six Skyrme models which present reasonable symmetry energies lying in the range of 28–35 MeV to analyze the behavior of several other bulk properties at zero temperature, as well as the critical temperature parameters. The models are also investigated to see whether they satisfy a stringent constraint recently proposed from heavy-ion experiments.