bluuebunny/crossref_metadata_2025 huggingface dataset:
Hepatitis C Virus Induces Epidermal Growth Factor Receptor Activation via CD81 Binding for Viral Internalization and Entry
Authors: Diao Jingyu , Pantua Homer , Ngu Hai , Komuves Laszlo , Diehl Lauri , Schaefer Gabriele , Kapadia Sharookh B.
Published: August 2012

While epidermal growth factor receptor (EGFR) has been shown to be important in the entry process for multiple viruses, including hepatitis C virus (HCV), the molecular mechanisms by which EGFR facilitates HCV entry are not well understood. Using the infectious cell culture HCV model (HCVcc), we demonstrate that the binding of HCVcc particles to human hepatocyte cells induces EGFR activation that is dependent on interactions between HCV and CD81 but not claudin 1. EGFR activation can also be induced by antibody mediated cross-linking of CD81. In addition, EGFR ligands that enhance the kinetics of HCV entry induce EGFR internalization and colocalization with CD81. While EGFR kinase inhibitors inhibit HCV infection primarily by preventing EGFR endocytosis, antibodies that block EGFR ligand binding or inhibitors of EGFR downstream signaling have no effect on HCV entry. These data demonstrate that EGFR internalization is critical for HCV entry and identify a hitherto-unknown association between CD81 and EGFR.
Incoming Influenza A Virus Evades Early Host Recognition, while Influenza B Virus Induces Interferon Expression Directly upon Entry
Authors: Österlund Pamela , Strengell Mari , Sarin L. Peter , Poranen Minna M. , Fagerlund Riku , Melén Krister , Julkunen Ilkka
Published: August 2012

The activation of the interferon (IFN) system, which is triggered largely by the recognition of viral nucleic acids, is one of the most important host defense reactions against viral infections. Although influenza A and B viruses, which both have segmented negative-strand RNA genomes, share major structural similarities, they have evolutionarily diverged, with total genetic incompatibility. Here we compare antiviral-inducing mechanisms during infections with type A and B influenza viruses in human dendritic cells. We observed that IFN responses are induced significantly faster in cells infected with influenza B virus than in cells infected with type A influenza virus and that the early induction of antiviral gene expression is mediated by the activation of the transcription factor IFN regulatory factor 3 (IRF3). We further demonstrate that influenza A virus infection activates IFN responses only after viral RNA (vRNA) synthesis, whereas influenza B virus induces IFN responses even if its infectivity is destroyed by UV treatment. Thus, initial viral transcription, replication, and viral protein synthesis are dispensable for influenza B virus-induced antiviral responses. Moreover, vRNA molecules from both type A and B viruses are equally potent activators of IFN induction, but incoming influenza B virus structures are recognized directly in the cytosol, while influenza A virus is able to evade early recognition. Collectively, our data provide new evidence of a novel antiviral evasion strategy for influenza A virus without a contribution of the viral NS1 protein, and this opens up new insights into different influenza virus pathogenicities.
Hepatitis C Virus Envelope Glycoprotein Fitness Defines Virus Population Composition following Transmission to a New Host
Authors: Brown Richard J. P. , Hudson Natalia , Wilson Garrick , Rehman Shafiq Ur , Jabbari Sara , Hu Ke , Tarr Alexander W. , Borrow Persephone , Joyce Michael , Lewis Jamie , Zhu Lin Fu , Law Mansun , Kneteman Norman , Tyrrell D. Lorne , McKeating Jane A. , Ball Jonathan K.
Published: August 2012

Genetic variability is a hallmark of RNA virus populations. However, transmission to a new host often results in a marked decrease in population diversity. This genetic bottlenecking is observed during hepatitis C virus (HCV) transmission and can arise via a selective sweep or through the founder effect. To model HCV transmission, we utilized chimeric SCID/Alb-uPA mice with transplanted human hepatocytes and infected them with a human serum HCV inoculum. E1E2 glycoprotein gene sequences in the donor inoculum and recipient mice were determined following single-genome amplification (SGA). In independent experiments, using mice with liver cells grafted from different sources, an E1E2 variant undetectable in the source inoculum was selected for during transmission. Bayesian coalescent analyses indicated that this variant arose in the inoculum pretransmission. Transmitted variants that established initial infection harbored key substitutions in E1E2 outside HVR1. Notably, all posttransmission E1E2s had lost a potential N-linked glycosylation site (PNGS) in E2. In lentiviral pseudoparticle assays, the major posttransmission E1E2 variant conferred an increased capacity for entry compared to the major variant present in the inoculum. Together, these data demonstrate that increased envelope glycoprotein fitness can drive selective outgrowth of minor variants posttransmission and that loss of a PNGS is integral to this improved phenotype. Mathematical modeling of the dynamics of competing HCV variants indicated that relatively modest differences in glycoprotein fitness can result in marked shifts in virus population composition. Overall, these data provide important insights into the dynamics and selection of HCV populations during transmission.
Membrane Interaction of the Portal Protein gp20 of Bacteriophage T4
Authors: Quinten Tobias A. , Kuhn Andreas
Published: August 2012

Assembly of the bacteriophage T4 head structure occurs at the cytoplasmic face of the inner membrane of
Escherichia coli
with the formation of proheads. The proheads contain an internal scaffolding core that determines the size and the structure of the capsid. In a mutant where the major shell protein gp23 was compromised, core structures without a shell had been detected. Such core structures were also found in the mutant T4
am20am23
. Since the mutation in gene 20 is at the N terminus of gp20, it was assumed that these core structures assemble in the absence of gp20. However, sequencing showed that the mutation introduces a new ribosome binding site that leads to a restart at codon 15. Although the mutant protein gp20s lacks the very N-terminal sequence, we found that it still binds to the membrane of the host cell and can initiate prohead assembly. This explains its activity to allow the assembly of core structures and proheads at the membrane surface. With a cross-linking approach, we show here that gp20 and gp20s are escorted by the chaperones DnaK, trigger factor, and GroEL and dock on the membrane at the membrane protein YidC.
A Mutation Deleting Sequences Encoding the Amino Terminus of Human Cytomegalovirus UL84 Impairs Interaction with UL44 and Capsid Localization
Authors: Strang Blair L. , Bender Brian J. , Sharma Mayuri , Pesola Jean M. , Sanders Rebecca L. , Spector Deborah H. , Coen Donald M.
Published: August 2012

Protein-protein interactions are required for many biological functions. Previous work has demonstrated an interaction between the human cytomegalovirus DNA polymerase subunit UL44 and the viral replication factor UL84. In this study, glutathione
S
-transferase pulldown assays indicated that residues 1 to 68 of UL84 are both necessary and sufficient for efficient interaction of UL84 with UL44
in vitro
. We created a mutant virus in which sequences encoding these residues were deleted. This mutant displayed decreased virus replication compared to wild-type virus. Immunoprecipitation assays showed that the mutation decreased but did not abrogate association of UL84 with UL44 in infected cell lysate, suggesting that the association in the infected cell can involve other protein-protein interactions. Further immunoprecipitation assays indicated that IRS1, TRS1, and nucleolin are candidates for such interactions in infected cells. Quantitative real-time PCR analysis of viral DNA indicated that the absence of the UL84 amino terminus does not notably affect viral DNA synthesis. Western blotting experiments and pulse labeling of infected cells with [
35
S]methionine demonstrated a rather modest downregulation of levels of multiple proteins and particularly decreased levels of the minor capsid protein UL85. Electron microscopy demonstrated that viral capsids assemble but are mislocalized in nuclei of cells infected with the mutant virus, with fewer cytoplasmic capsids detected. In sum, deletion of the sequences encoding the amino terminus of UL84 affects interaction with UL44 and virus replication unexpectedly, not viral DNA synthesis. Mislocalization of viral capsids in infected cell nuclei likely contributes to the observed decrease in virus replication.
Cryo-Electron Tomography of Rubella Virus
Authors: Battisti Anthony J. , Yoder Joshua D. , Plevka Pavel , Winkler Dennis C. , Mangala Prasad Vidya , Kuhn Richard J. , Frey Teryl K. , Steven Alasdair C. , Rossmann Michael G.
Published: August 2012

Rubella virus is the only member of the
Rubivirus
genus within the
Togaviridae
family and is the causative agent of the childhood disease known as rubella or German measles. Here, we report the use of cryo-electron tomography to examine the three-dimensional structure of rubella virions and compare their structure to that of Ross River virus, a togavirus belonging the genus
Alphavirus
. The ectodomains of the rubella virus glycoproteins, E1 and E2, are shown to be organized into extended rows of density, separated by 9 nm on the viral surface. We also show that the rubella virus nucleocapsid structure often forms a roughly spherical shell which lacks high density at its center. While many rubella virions are approximately spherical and have dimensions similar to that of the icosahedral Ross River virus, the present results indicate that rubella exhibits a large degree of pleomorphy. In addition, we used rotation function calculations and other analyses to show that approximately spherical rubella virions lack the icosahedral organization which characterizes Ross River and other alphaviruses. The present results indicate that the assembly mechanism of rubella virus, which has previously been shown to differ from that of the alphavirus assembly pathway, leads to an organization of the rubella virus structural proteins that is different from that of alphaviruses.
Acute Diarrhea in West African Children: Diverse Enteric Viruses and a Novel Parvovirus Genus
Authors: Phan Tung G. , Vo Nguyen P. , Bonkoungou Isidore J. O. , Kapoor Amit , Barro Nicolas , O'Ryan Miguel , Kapusinszky Beatrix , Wang Chunling , Delwart Eric
Published: August 2012

Parvoviruses cause a variety of mild to severe symptoms or asymptomatic infections in humans and animals. During a viral metagenomic analysis of feces from children with acute diarrhea in Burkina Faso, we identified in decreasing prevalence nucleic acids from anelloviruses, dependoviruses, sapoviruses, enteroviruses, bocaviruses, noroviruses, adenoviruses, parechoviruses, rotaviruses, cosavirus, astroviruses, and hepatitis B virus. Sequences from a highly divergent parvovirus, provisionally called bufavirus, were also detected whose NS1 and VP1 proteins showed <39% and <31% identities to those of previously known parvoviruses. Four percent of the fecal samples were PCR positive for this new parvovirus, including a related bufavirus species showing only 72% identity in VP1. The high degree of genetic divergence of these related genomes from those of other parvoviruses indicates the presence of a proposed new
Parvoviridae
genus containing at least two species. Studies of the tropism and pathogenicity of these novel parvoviruses will be facilitated by the availability of their genome sequences.
Spatiotemporal Dynamics of Adenovirus Membrane Rupture and Endosomal Escape
Authors: Maier Oana , Marvin Shauna A. , Wodrich Harald , Campbell Edward M. , Wiethoff Christopher M.
Published: August 2012

A key step in adenovirus cell entry is viral penetration of cellular membranes to gain access to the cytoplasm and deliver the genome to the nucleus. Yet little is known about this important event in the adenoviral life cycle. Using the cytosolic protein galectin-3 (gal3) as a marker of membrane rupture with both live- and fixed-cell imaging, we demonstrate that in the majority of instances, exposure of pVI and recruitment of gal3 to ruptured membranes occur early at or near the cell surface and occur minimally in EEA-1-positive (EEA-1
+
) early endosomes or LAMP-1
+
late endosomes/lysosomes. Live-cell imaging of Ad5 egress from gal3
+
endosomes occurs most frequently from perinuclear locations. While the Ad5 capsid is observed escaping from gal3
+
endosomes, pVI appears to remain associated with the gal3
+
ruptured endosomes. Thus, Ad5 membrane rupture and endosomal escape appear to be both spatially and temporally distinct events.
Human Rotavirus-Specific IgM Memory B Cells Have Differential Cloning Efficiencies and Switch Capacities and Play a Role in Antiviral ImmunityIn Vivo
Authors: Narváez Carlos F. , Feng Ningguo , Vásquez Camilo , Sen Adrish , Angel Juana , Greenberg Harry B. , Franco Manuel A.
Published: August 2012

Protective immunity to rotavirus (RV) is primarily mediated by antibodies produced by RV-specific memory B cells (RV-mBc). Of note, most of these cells express IgM, but the function of this subset is poorly understood. Here, using limiting dilution assays of highly sort-purified human IgM+mBc, we found that 62% and 21% of total (non-antigen-specific) IgM+and RV-IgM+mBc, respectively, switchedin vitroto IgG production after polyclonal stimulation. Moreover, in these assays, the median cloning efficiencies of total IgM+(17%) and RV-IgM+(7%) mBc were lower than those of the corresponding switched (IgG+IgA+) total (34%) and RV-mBc (17%), leading to an underestimate of their actual frequency. In order to evaluate thein vivorole of IgM+RV-mBc in antiviral immunity, NOD/Shi-scid interleukin-2 receptor-deficient (IL-2Rγnull) immunodeficient mice were adoptively transferred highly purified human IgM+mBc and infected with virulent murine rotavirus. These mice developed high titers of serum human RV-IgM and IgG and had significantly lower levels than control mice of both antigenemia and viremia. Finally, we determined that human RV-IgM+mBc are phenotypically diverse and significantly enriched in the IgMhiIgDlowsubset. Thus, RV-IgM+mBc are heterogeneous, occur more frequently than estimated by traditional limiting dilution analysis, have the capacity to switch Ig classin vitroas well asin vivo, and can mediate systemic antiviral immunity.
Hepatitis C Virus (HCV) Induces Formation of Stress Granules Whose Proteins Regulate HCV RNA Replication and Virus Assembly and Egress
Authors: Garaigorta Urtzi , Heim Markus H. , Boyd Bryan , Wieland Stefan , Chisari Francis V.
Published: August 2012

Stress granules (SGs) are cytoplasmic structures that are induced in response to environmental stress, including viral infections. Here we report that hepatitis C virus (HCV) triggers the appearance of SGs in a PKR- and interferon (IFN)-dependent manner. Moreover, we show an inverse correlation between the presence of stress granules and the induction of IFN-stimulated proteins, i.e., MxA and USP18, in HCV-infected cells despite high-level expression of the corresponding MxA and USP18 mRNAs, suggesting that interferon-stimulated gene translation is inhibited in stress granule-containing HCV-infected cells. Finally, in short hairpin RNA (shRNA) knockdown experiments, we found that the stress granule proteins T-cell-restricted intracellular antigen 1 (TIA-1), TIA1-related protein (TIAR), and RasGAP-SH3 domain binding protein 1 (G3BP1) are required for efficient HCV RNA and protein accumulation at early time points in the infection and that G3BP1 and TIA-1 are required for intracellular and extracellular infectious virus production late in the infection, suggesting that they are required for virus assembly. In contrast, TIAR downregulation decreases extracellular infectious virus titers with little effect on intracellular RNA content or infectivity late in the infection, suggesting that it is required for infectious particle release. Collectively, these results illustrate that HCV exploits the stress granule machinery at least two ways: by inducing the formation of SGs by triggering PKR phosphorylation, thereby downregulating the translation of antiviral interferon-stimulated genes, and by co-opting SG proteins for its replication, assembly, and egress.
Evaluation of Different Moxibustion Doses for Lumbar Disc Herniation: Multicentre Randomised Controlled Trial of Heat-Sensitive Moxibustion Therapy
Authors: Chen Mingren , Chen Rixin , Xiong Jun , Chi Zhenhai , Sun Jianhua , Su Tongsheng , Zhou Meiqi , Yi Fan , Zhang Bo
Published: August 2012

Background

There is some evidence for the effectiveness of moxibustion for the treatment of lumbar disc herniation (LDH), but it remains unclear what dose is optimal.

Objective

To compare the effectiveness of a new technique of individualised ‘sensitivity elimination’ dose versus a standardised 15 min dose in the treatment of LDH.

Methods

This study was a multicentre (four centres in China), randomised, controlled trial with two parallel arms (group A, individualised sensitivity elimination dose; group B, standardised dose). The most heat-sensitised acupuncture point from the triangle bound by BL25 and GV2 was selected. Both groups received 18 sessions over 2 weeks. The outcome was evaluated by Modified Japanese Orthopaedic Association scale (M-JOA) score before and after treatment and at 6-month follow-up examination. All main analyses were by intention to treat.

Results

A total of 96 patients were included. A Significant difference of total M-JOA score was noted between the groups at weeks 1 and 2 (p<0.05). Significant differences were also evident during the follow-up period (p<0.01). The mean duration of moxibustion was 42.7±5.4 (range, 22–58) minutes in the experimental group.

Conclusions

The effectiveness of the individualised sensitivity elimination dose appears superior to the standardised dose in the treatment of LDH. Only 15 min moxibustion in the conventional dose group seemed insufficient to elicit the satisfactory clinical effects obtained by heat-sensitive moxibustion therapy. However, in view of some limitations of this study further research is necessary before this can be stated conclusively.

Trial Registration

Controlled Clinical Trials: ChiCTR-TRC-09000602.
Recurrent episodic hypoxaemic respiratory failure following a stroke
Authors: Foo Aaron S C , Tan Zi Kheng , Lee Evelyn , Koh Nien Yue
Published: August 2012

A 68-year-old man with no cardiovascular risk factors was admitted with a stroke because of multiple brain infarcts in different vascular territories. He required mechanical ventilation for hypoxia as a result of aspiration pneumonia. Subsequent recovery was hindered by episodic, unexplained hypoxia. Investigations excluded pulmonary embolism, pulmonary hypertension and severe lung diseases. Transthoracic echocardiography (TTE) with saline bubble contrast showed mild, delayed, right-to-left shunting, thought to represent an insignificant, intrapulmonary, non-cardiac shunt. Hypoxic episodes worsened, requiring admission from community rehabilitation hospital to our centre and another period of mechanical ventilation. Elevated alveolar-arterial gradients indicated a non-hypoventilatory cause. Repeat TTE bubble contrast study and transoesophageal echocardiography (TOE) demonstrated a patent foramen ovale (PFO) with large shunt potential, associated with an aneurysmal interatrial septum. This provided a unifying explanation for cryptogenic stroke and recurrent hypoxaemia. After percutaneous PFO closure hypoxic episodes ceased and he returned successfully to rehabilitation.
Self-perceived psychosomatic health in Swedish children, adolescents and young adults: an internet-based survey over time
Authors: Friberg Peter , Hagquist Curt , Osika Walter
Published: August 2012

Objectives

The authors investigated self-perceived psychosomatic health in young people (10–24 years of age) in Sweden and analysed different samples during the years 2005 and 2007–2010 via a community website.

Design

Repeated cross-sectional surveys: (1) single question on a single day in 2005. (2) One specific question delivered on each of eight separate days in 2005. (3) The same eight questions delivered to smaller groups on the same day in 2007 and then again to randomly selected subjects in 2010.

Setting

Validated questionnaires launched on the internet by a recognised Swedish community site. Study participants were invited to answer questions about their health with full anonymity as they logged into their personal area.

Participants

10–24-year-old children, adolescents and young adults.

Primary and secondary outcome measures

Self-reported psychosomatic health in terms of sex and age over time.

Results

A large number of responses were obtained (up to 140 000). The response rate for the single item on stress was 41%. A high percentage of young subjects responded that they felt stressed very often/often; the numbers were higher for women (47%) than for men (29%). Older teenaged women had more psychosomatic complaints than did men of similar ages; in contrast, among 10–12-year-old children, the percentage of psychosomatic complaints was similar for men and women. When comparing results obtained in 2010 with those obtained in 2007, young people of both sexes had a slightly better self-perceived health status in 2007.

Conclusions

During the period 2005–2010 a high percentage of young people, particularly females, 16–18 years of age, had psychosomatic complaints and considered themselves as being often or very often stressed. These complaints were more pronounced in the older age groups. When directing questions to a large community, internet-based surveys appear to be valuable tools.
Age differences in the associations between sick leave and aspects of health, psychosocial workload and family life: a cross-sectional study
Authors: Donders Nathalie C G M , Bos Judith T , van der Velden Koos , van der Gulden Joost W J
Published: August 2012

Objectives

To investigate differences in associations between sick leave and aspects of health, psychosocial workload, family life and work–family interference between four age groups (<36, 36–45, 46–55 and 55+ years).

Design

A cross-sectional study; a questionnaire was sent to the home addresses of all employees of a university.

Setting

A Dutch university.

Participants

1843 employees returned the questionnaire (net response: 49.1%). The age distribution was as follows: <36: 32%; 36–45: 26%; 46–55: 27% and 55+: 12%.

Primary outcomes

Frequent sick leave (FSL, ≥3 times in the past 12 months) and prolonged sick leave (PSL, >2 weeks in total in the past 12 months). Differences between the age groups in independent variables and outcomes were investigated. Logistic regression analysis was used to calculate associations between various variables and the sick leave outcomes. Interaction terms were included to detect differences between the age groups.

Results

Age differences were found for many work- and family-related characteristics but not in the mean scores for health-related aspects. Presence of chronic disease was reported more frequently with increasing age. The 55+ age group had almost two times less chance of FSL, but 1.6 times more chance of PSL than the <36 age group. Age moderates the associations between career opportunities, partner's contribution in domestic tasks and sex, and FSL. Job security and pay, support from supervisor, challenging work and being breadwinner have different associations with PSL. However, life events in private lives and perceived health complaints are important in all age groups. FSL and PSL have some determinants in common, but there are differences between the outcomes as well.

Conclusions

Age should be treated as a variable of interest instead of a control variable. Employers and occupational physicians need to be aware that each phase in life has specific difficulties that can lead to FSL and PSL.
Psychosocial risk factors, job characteristics and self-reported health in the Paris Military Hospital Group (PMHG): a cross-sectional study
Authors: Ferrand Jean-François , Verret Catherine , Trichereau Julie , Rondier Jean-Philippe , Viance Patrice , Migliani René
Published: August 2012

Objectives

To investigate the associations between psychosocial risk factors and self-reported health, taking into account other occupational risk factors.

Design

Cross-sectional survey using a self-administered questionnaire.

Setting

The three military hospitals in Paris, France.

Participants

Surveys were distributed to 3173 employees (1807 military and 1336 civilian), a total of 1728 employees completed surveys. Missing data prohibited the use of 26 surveys.

Primary and secondary outcome measures

The authors used Karasek's model in order to identify psychosocial factors (psychological demands, decisional latitude, social support) in the workplace. The health indicator studied was self-reported health. Adjustments were made for covariates: age, gender, civil or military status, work injury, ergonomic score, physical and chemical exposures, and occupational profile. Occupational profile was defined by professional category, department, work schedule, supervisor status and service-related length in the hospital.

Results

Job strain (defined as high psychological demands and low decisional latitude) (adjusted OR 2.1, 95% CI 1.5 to 2.8, p<0.001) and iso-strain (job strain with low social support) were significantly associated with moderate or poor self-reported health. Among covariates, occupational profile (p<0.001) and an unsatisfactory ergonomic score (adjusted OR 2.3 95% CI 1.6 to 3.2, p<0.001) were also significantly associated with moderate or poor self-reported health.

Conclusions

The results support findings linking moderate or poor self-reported health to psychosocial risk factors. The results of this study suggest that workplace interventions that aim to reduce exposure to psychological demands as well as to increase decisional latitude and social support could help improve self-reported health.
Mapping the receptivity of malaria risk to plan the future of control in Somalia
Authors: Noor Abdisalan Mohamed , Alegana Victor Adagi , Patil Anand Prabhakar , Moloney Grainne , Borle Mohammed , Yusuf Fahmi , Amran Jamal , Snow Robert William
Published: August 2012

Objectives

To measure the receptive risks of malaria in Somalia and compare decisions on intervention scale-up based on this map and the more widely used contemporary risk maps.

Design

Cross-sectional communityPlasmodium falciparumparasite rate (PfPR) data for the period 2007–2010 corrected to a standard age range of 2 to <10 years (PfPR2–10) and used within a Bayesian space–time geostatistical framework to predict the contemporary (2010) meanPfPR2–10and the maximum annual meanPfPR2–10(receptive) from the highest predictedPfPR2–10value over the study period as an estimate of receptivity.

Setting

Randomly sampled communities in Somalia.

Participants

Randomly sampled individuals of all ages.

Main outcome measure

Cartographic descriptions of malaria receptivity and contemporary risks in Somalia at the district level.

Results

The contemporary annualPfPR2–10map estimated that all districts (n=74) and population (n=8.4 million) in Somalia were under hypoendemic transmission (≤10%PfPR2–10). Of these, 23% of the districts, home to 13% of the population, were under transmission of <1%PfPR2–10. About 58% of the districts and 55% of the population were in the risk class of 1% to <5%PfPR2–10. In contrast, the receptivity map estimated 65% of the districts and 69% of the population were under mesoendemic transmission (>10%–50%PfPR2–10) and the rest as hypoendemic.

Conclusion

Compared with maps of receptive risks, contemporary maps of transmission mask disparities of malaria risk necessary to prioritise and sustain future control. As malaria risk declines across Africa, efforts must be invested in measuring receptivity for efficient control planning.
Improper cause-of-death statements by specialty of certifying physician: a cross-sectional study in two medical centres in Taiwan
Authors: Cheng Tain-Junn , Lee Fang-Chuan , Lin Shio-Jean , Lu Tsung-Hsueh
Published: August 2012

Objective

To determine the frequency of various types of improper cause-of-death (COD) statements reported on death certificates and whether the frequency differed by specialty of the certifying physician.

Design

Cross-sectional descriptive study.

Setting

2 medical centres in Tainan, Taiwan.

Participants

A total of 2520 death certificates issued by 230 physicians.

Main outcome measures

4 types of improper COD statements based on the criteria of correctness of the COD causal sequence and the level of specificity of underlying COD selected.

Results

Of 2520 death certificates analysed, 502 (19.9%) had at least one type of improper COD statement. However, only 235 (9.3%) sustained major errors, that is, 91 (3.6%) reported incorrect causal sequence and 144 (5.7%) reported only mechanism(s) of death (such as respiratory failure, heart failure, sepsis and acidosis). The improper reporting rate was highest among nephrologists (53%, 24/45), followed by infectious diseases physicians (45%, 29/65) and was lowest among oncologists (6%, 57/995).

Conclusions

About one-fifth issued death certificates sustained improper COD statements and only one-tenth had noteworthy errors that would threaten the quality of COD statistics. The frequency varied by specialty of the certifying physician because physicians in different specialties manage different types of diseases and conditions with contrasting complexities in terms of determining the causal sequence and specificity of COD statements.
Dental status and incident falls among older Japanese: a prospective cohort study
Authors: Yamamoto Tatsuo , Kondo Katsunori , Misawa Jimpei , Hirai Hiroshi , Nakade Miyo , Aida Jun , Kondo Naoki , Kawachi Ichiro , Hirata Yukio
Published: August 2012

Objective

To examine if self-reported number of teeth, denture use and chewing ability are associated with incident falls.

Design

Longitudinal cohort study (the Aichi Gerontological Evaluation Study).

Setting

5 Japanese municipalities.

Participants

1763 community-dwelling individuals aged 65 years and older without experience of falls within the previous year at baseline.

Main outcome measures

Self-reported history of multiple falls during the past year at the follow-up survey about 3 years later. Baseline data on the number of teeth present and/or denture use and chewing ability were collected using self-administered questionnaires. Logistic regression analyses controlled for sex, age, functional disability during follow-up period, depression, self-rated health and educational attainment.

Results

86 (4.9%) subjects reported falls at the follow-up survey. Logistic regression models fully adjusted for all covariates showed that subjects having 19 or fewer teeth but not using dentures had a significantly increased risk for incident falls (OR 2.50, 95% CI 1.21 to 5.17, p=0.013) compared with those having 20 or more teeth. Among subjects with 19 or fewer teeth, their risk of falls was not significantly elevated so long as they wore dentures (OR 1.36, 95% CI 0.76 to 2.45, p=0.299). No significant association was observed between chewing ability and incident falls in the fully adjusted model.

Conclusions

Having 19 or fewer teeth but not using dentures was associated with higher risk for the incident falls in older Japanese even after adjustment for multiple covariates. Dental care to prevent tooth loss and denture treatment for older people might prevent falls, although the authors cannot exclude the possibility that the association is due to residual confounding.
The coronary CT angiography vision protocol: a prospective observational imaging cohort study in patients undergoing non-cardiac surgery
Authors: Sheth Tej , Butler Craig , Chow Benjamin , Chan M T V , Mitha Ayesha , Nagele Peter , Tandon Vikas , Stewart Lori , Graham Michelle , Choi G Y S , Kisten T , Woodard P K , Crean Andrew , Abdul Aziz Y F , Karthikeyan G , Chow C K , Szczeklik W , Markobrada M , Mastracci T. , Devereaux P J
Published: August 2012

Introduction

At present, physicians have a limited ability to predict major cardiovascular complications after non-cardiac surgery and little is known about the anatomy of coronary arteries associated with perioperative myocardial infarction. We have initiated the Coronary CT Angiography (CTA) VISION Study to (1) establish the predictive value of coronary CTA for perioperative myocardial infarction and death and (2) describe the coronary anatomy of patients that have a perioperative myocardial infarction.

Methods and analysis

The Coronary CTA VISION Study is prospective observational study. Preoperative coronary CTA will be performed in 1000–1500 patients with a history of vascular disease or at least three cardiovascular risk factors who are undergoing major elective non-cardiac surgery. Serial troponin will be measured 6–12 h after surgery and daily for the first 3 days after surgery. Major vascular outcomes at 30 days and 1 year after surgery will be independently adjudicated.

Ethics and dissemination

Coronary CTA results in a measurable radiation exposure that is similar to a nuclear perfusion scan (10–12 mSV). Treating physicians will be blinded to the CTA results until 30 days after surgery in order to provide the most unbiased assessment of its prognostic capabilities. The only exception will be the presence of a left main stenosis >50%. This approach is supported by best available current evidence that, excluding left main disease, prophylatic revascularisation prior to non-cardiac surgery does not improve outcomes. An external safety and monitoring committee is overseeing the study and will review outcome data at regular intervals. Publications describing the results of the study will be submitted to major peer-reviewed journals and presented at international medical conferences.
Could a peer-led intervention increase uptake of chlamydia screening? A proof of principle pilot study
Authors: Loaring Jessica , Hickman Matthew , Oliver Isabel , Campbell Rona , Trotter Caroline , Macleod John , Pye Karl , Crichton Joanna , Horner Paddy
Published: August 2012

Background

Uptake of the English National Chlamydia Screening Programme is lower than predicted necessary to result in a rapid fall in chlamydia prevalence. Peer-led approaches may increase screening uptake but their feasibility and acceptability to young people is not known.

Methods

Focus groups and interviews with young women and men. Following interview, chlamydia postal kits were introduced to participants and their opinions on giving these out to their peers sought. Participants were asked for their views and experiences of discussing chlamydia screening and distributing kits to their friends 4–8 weeks after the focus group/interview. All kits returned to the laboratory over a 9-month period were recorded.

Results

Six men (mean age 19 years) and six women (mean age 20 years) were recruited. In total 45 kits were distributed, 33 (73%) to female participants. 22 (67%) and 3 (25%) of kits given to females and males, respectively, were given to peers. Ten kits (22%; seven female, three male) all of which had been given out by females, were returned for testing. Participants generally felt positive about the idea of peer-led screening (PLS) using postal kits. However, embarrassment was a key theme, particularly among men. Generally women but not men were able to discuss PLS among their close friends. Both sexes felt PLS would be easier if kits were readily available in multiple sites, and chlamydia screening was more widely promoted.

Conclusion

Female PLS but not male PLS was successful in recruiting peers to participate in chlamydia screening. An evaluation of the acceptability and cost-effectiveness of PLS is now indicated.
Prioritization criteria for enterprise resource planning systems selection for civil construction companies: a multicriteria approach
Authors: Méxas Mirian Picinini , Quelhas Osvaldo Luiz Gonçalves , Costa Helder Gomes
Published: August 2012

In this study, as a first step, a set of criteria and subcriteria was proposed for enterprise resource planning (ERP) systems selection for companies in the civil construction industry that is based on a review of the literature concerning the application of multicriteria models for evaluating ERP systems. Subsequently, after validation of these criteria by a group of information technology specialists, a field survey was developed based on the administration of a questionnaire and the use of the analytic hierarchy process. This survey enabled us to perform an analysis of the judgment consistency of the 11 respondents who participated in this study and to capture their perceptions of criteria importance. The survey revealed that respondents considered the software criterion to be the most important and showed the importance of subcriteria within groups of criteria, which greatly contributed to the decision-making process in ERP systems selection.
Application of acoustic emission for monitoring shear behavior of bonded concrete–rock joints under direct shear test
Authors: Moradian Z.A. , Ballivy G. , Rivard P.
Published: August 2012

Studying shear behavior and failure mechanism of concrete–rock interfaces between concrete structures and rock mass is highly important. To this end, laboratory direct shear tests were conducted on several bonded interfaces. The effect of normal stress, displacement rate, and bonding percentage on shear behavior of bonded joints were also evaluated. The results showed that the adhesive bond between concrete and rock has the most important effect on shear mechanism of concrete–rock interfaces. When the normal load is low, the asperities do not contribute in shear process, so the shear strength of the joints is governed by adhesive bond. The only contribution of the asperities is that they show a small peak after bond breaking peak. When the normal load is high, the asperities break simultaneously with adhesive bond and they show their contribution in the whole shear process. In a constant normal load, by decreasing bonding percentage, the brittle failure of the bonded joints is changed into softening failure because of less contribution of the adhesive bond and more contribution of the rough asperities in joint failure. Acoustic emission (AE) monitoring of bonded joints showed that for all different tested samples under various loading conditions, there has been no or very few AE activities before adhesive bond breaking point, indicating that other parameters (roughness, normal load, displacement rate) are impressed by adhesive bond and maximum shear strength is determined by this parameter.
Mitigating shrinkage cracking in stucco through the replacement of fine aggregate with expanded perlite
Authors: Mamun Muhammad , Bindiganavile Vivek
Published: August 2012

This paper describes a quantitative study on shrinkage cracking in stucco. Two series of mixes were examined with the binder to fine aggregate volumetric ratio of 0.20 and 0.25, respectively. In each series, specially engineered expanded perlite was incorporated as a replacement to the fine aggregate at up to 75% by volume. An environmental chamber was setup to create extreme conditions for moisture loss through sustained high temperature and low humidity. Commercially recommended stucco mixes were cast into plates, which were evaluated for linear and volumetric shrinkage. At the same time, crack growth at the end of a 48 h exposure period was evaluated for total length and area. It was found that while adding expanded perlite did not notably reduce the total linear or volumetric shrinkage, it significantly lessened crack development. This was attributed to the increase in tensile strain capacity imparted by the expanded perlite, as evidenced from flexural testing.
Strategic Highway Research Program gyratory compaction for predicting air voids of Saskatchewan SPS-9A asphalt mixes after 10 years of performance in the field
Authors: Salifu Aziz , Berthelot Curtis , Anthony Ania , Marjerison Brent
Published: August 2012

Many Saskatchewan provincial highways exhibit permanent deformation that is mostly attributed to reduction in air voids in hot mix asphalt concrete surfacing. The Saskatchewan Ministry of Highways and Infrastructure (MHI) currently use the Marshall compaction method for hot mix asphalt concrete (HMAC) design and placement quality control and quality assurance. It has been found that the Marshall compaction method does not accurately predict field air voids. Therefore, MHI identified the need to evaluate the SuperpaveTM gyratory compaction method to predict field air voids of typical Saskatchewan asphalt mixes. This paper presents a summary of laboratory and field volumetric as well as rapid triaxial mechanistic material properties of typical Saskatchewan asphalt mixes. This research considered seven asphalt mixes from the Radisson Specific Pavement Study (SPS)-9A test site comprising two conventional Saskatchewan Marshall Type 71 mixes, five SuperpaveTM mixes, and a SuperpaveTM recycled mix. This research determined that Marshall compaction and the gyratory compaction at 1.25° gyration angle underestimate the collapse of field air voids. This research also showed that the gyratory compaction method at 2.00° angle of gyration more accurately predicted field air voids of the asphalt mixes constructed as part of test site.
Characterization of sedimentation pattern in reservoirs
Authors: Rahmanian Mohammad Reza , Banihashemi Mohammad Ali
Published: August 2012

The observed sedimentation data from some Iranian large reservoirs were used to characterize sediment distribution patterns within these reservoirs and a modified approach was developed. This new idea is of an empirical nature and is based on some parameters obtained from the minimum stream power principle. The main advantage of this new characterization is that it eliminates the need for classification of the dam based on any extra data and solely depends on the characteristics of the reservoir geometry. It also rectifies some practical difficulties for application of the existing method. The developed technique achieved by this study is recommended for preliminary design stages to interpret long-term cumulative distribution of sediment and is applicable for reservoirs that have sediment particles that are mainly of fine-grained material.
Adaptive route choice model for public transit systems: an application of Markov decision processes
Authors: Rouhieh Behzad , Alecsandru Ciprian
Published: August 2012

Over the past couple of decades the advancements in the areas of information and computational technology allowed for a variety of intelligent transportation systems developments and deployments. This study investigates an advanced traveler information system (ATIS) and (or) an advanced public transit system (APTS) adaptive and real-time transit routing component. The proposed methodology is applied to bus routes with fixed, predefined bus line alignments. It is shown that routing buses on such systems can be modeled in real-time by employing an associated Markov chain with reward model to minimize the impact of congested traffic conditions on the travelers and the overall operation cost of the transit system. A case study using a traffic and transit data from a real-world bus line was used to apply the proposed bus routing approach. It was found that under certain traffic congestion conditions buses should be re-routed to minimize their travel time and the associated system costs. The hypothetical congestion scenarios investigated show that individual bus travel time delays range between 50 and 740 s when the proposed adaptive routing is employed. The proposed methodology is also suitable for application to transit systems that run on a demand-adaptive basis (the bus line alignment changes with the travelers demand). Additional calibration and future integration of the system into specific ATIS and (or) APTS user services will be investigated.
Elliptical hollow section T and X connections
Authors: Haque Tarana , Packer Jeffrey A.
Published: August 2012

Elliptical hollow sections (EHS) are the newest steel shape to have emerged in the construction industry. They have been incorporated in a variety of structures around the world, including Canada, without structural design guidelines. To date, EHS are completely absent from Canadian codes and guides. A possible application of EHS is within truss-systems and, as such, a research project has been undertaken to investigate the behaviour of EHS-to-EHS welded connections. Twelve T and X connection tests have been performed to study the effect of connection angle, orientation type, and loading sense. Two methods to predict connection capacities and failure modes are investigated: an equivalent circular hollow section (CHS) approach and an equivalent rectangular hollow section (RHS) approach. The equivalent RHS approach proved to be more successful at capturing the actual failure mode of welded EHS-to-EHS connections and is therefore recommended at this time as a preliminary design method for EHS truss-type connections.
CHARM MESON MIXING: AN EXPERIMENTAL REVIEW
Authors: CHAVEZ CARLOS A. , COWAN RAY F. , LOCKMAN W. S.
Published: August 2012

We review current experimental results on charm mixing and CP violation. We survey experimental techniques, including time-dependent, time-independent, and quantum-correlated measurements. We review techniques that use a slow pion tag from D*+→π+D0+ c.c. decays and those that do not, and cover two-body and multi-body D0 decay modes. We provide a summary of D-mixing results to date and comment on future experimental prospects at the LHC and other new or planned facilities.
GRAVITATIONAL SHOCKS AS A KEY INGREDIENT OF GAMMA-RAY BURSTS
Authors: AVGOUSTIDIS ANASTASIOS , JIMENEZ RAUL , ÁLVAREZ-GAUMÉ LUIS , VÁZQUEZ-MOZO MIGUEL A.
Published: August 2012

We identify a novel physical mechanism that may be responsible for energy release in γ-ray bursts. Radial perturbations in the neutron core, induced by its collision with collapsing outer layers during the early stages of supernova explosions, can trigger a gravitational shock, which can readily eject a small but significant fraction of the collapsing material at ultra-relativistic speeds. The development of such shocks is a strong-field effect arising in near-critical collapse in general relativity and has been observed in numerical simulations in various contexts, including, in particular, radially perturbed neutron star collapse, albeit for a tiny range of initial conditions. Therefore, this effect can be easily missed in numerical simulations if the relevant parameter space is not exhaustively investigated. In the proposed picture, the observed rarity of γ-ray bursts would be explained if the relevant conditions for this mechanism appear in only about one in every 104–105 core collapse supernovae. We also mention the possibility that near-critical collapse could play a role in powering the central engines of active galactic nuclei.