bluuebunny/crossref_metadata_2025 huggingface dataset:
Relative Contributions of
Halobacteriovorax
and Bacteriophage to Bacterial Cell Death under Various Environmental Conditions
Authors: Chen Huan , Laws Edward A. , Martin Julio L. , Berhane Timkhite-Kulu , Gulig Paul A. , Williams Henry N.
Published: August 2018

The role of protists and bacteriophages in bacterial predation in the microbial food web has been well studied. There is mounting evidence that
Bdellovibrio
and like organisms (BALOs) also contribute to bacterial mortality and, in some cases, more so than bacteriophages. A full understanding of the ecologic function of the microbial food web requires recognition of all major predators and the magnitude of each predator’s contribution. Here we investigated the contribution of
Halobacteriovorax
, one of the BALOs, and bacteriophages when incubated with their common prey,
Vibrio vulnificus
, in a seawater microcosm. We observed that
Halobacteriovorax
was the greatest responder to the prey, increasing 18-fold with a simultaneous 4.4-log-unit reduction of
V. vulnificus
at 40 h, whereas the bacteriophage population showed no significant increase. In subsequent experiments to formulate a medium that would support the predatory activities and replication of both predators, low-nutrient media favored the predation and replication of the
Halobacteriovorax
, whereas higher-nutrient media enhanced phage growth. The greatest prey reduction and replication of both
Halobacteriovorax
and phage were observed in media with moderate nutrient levels. Additional experiments show that the predatory activities of both predators were influenced by environmental conditions, specifically, temperature and salinity. The two predators combined exerted greater control on
V. vulnificus
, a synergism that may be exploited for practical applications to reduce bacterial populations. These findings suggest that along with bacteriophage and protists,
Halobacteriovorax
has the potential to have a prominent role in bacterial mortality and cycling of nutrients, two vital ecologic functions.

IMPORTANCE
Although much has been reported about the marine microbial food web and the role of micropredators, specifically viruses and protists, the contribution of
Bdellovibrio
-like predators has largely been ignored, posing a major gap in understanding food web processes. A complete scenario of the microbial food web cannot be developed until the roles of all major micropredators and the magnitude of their contributions to bacterial mortality, structuring of microbial communities, and cycling of nutrients are assessed. Here we show compelling evidence that
Halobacteriovorax
, a predatory bacterium, is a significant contributor to bacterial death and, in some cases, may rival viruses as agents of bacterial mortality. These results advance current understanding of the microbial loop and top-down control on the bacterial community.
Cyclic Enterobacterial Common Antigen Maintains the Outer Membrane Permeability Barrier of Escherichia coli in a Manner Controlled by YhdP
Authors: Mitchell Angela M. , Srikumar Tharan , Silhavy Thomas J.
Published: August 2018

Gram-negative bacteria have an outer membrane (OM) impermeable to many toxic compounds that can be further strengthened during stress. In
Enterobacteriaceae
, the envelope contains enterobacterial common antigen (ECA), a carbohydrate-derived moiety conserved throughout
Enterobacteriaceae
, the function of which is poorly understood. Previously, we identified several genes in
Escherichia coli
K-12 responsible for an RpoS-dependent decrease in envelope permeability during carbon-limited stationary phase. For one of these,
yhdP
, a gene of unknown function, deletion causes high levels of both vancomycin and detergent sensitivity, independent of growth phase. We isolated spontaneous suppressor mutants of
yhdP
with loss-of-function mutations in the ECA biosynthesis operon. ECA biosynthesis gene deletions suppressed envelope permeability from
yhdP
deletion independently of envelope stress responses and interactions with other biosynthesis pathways, demonstrating suppression is caused directly by removing ECA. Furthermore,
yhdP
deletion changed cellular ECA levels and
yhdP
was found to co-occur phylogenetically with the ECA biosynthesis operon. Cells make three forms of ECA: ECA lipopolysaccharide (LPS), an ECA chain linked to LPS core; ECA phosphatidylglycerol, a surface-exposed ECA chain linked to phosphatidylglycerol; and cyclic ECA, a cyclized soluble ECA molecule found in the periplasm. We determined that the suppression of envelope permeability with
yhdP
deletion is caused specifically by the loss of cyclic ECA, despite lowered levels of this molecule found with
yhdP
deletion. Furthermore, removing cyclic ECA from wild-type cells also caused changes to OM permeability. Our data demonstrate cyclic ECA acts to maintain the OM permeability barrier in a manner controlled by YhdP.

IMPORTANCE
Enterobacterial common antigen (ECA) is a surface antigen made by all members of
Enterobacteriaceae
, including many clinically relevant genera (e.g.,
Escherichia
,
Klebsiella
,
Yersinia
). Although this surface-exposed molecule is conserved throughout
Enterobacteriaceae
, very few functions have been ascribed to it. Here, we have determined that the periplasmic form of ECA, cyclic ECA, plays a role in maintaining the outer membrane permeability barrier. This activity is controlled by a protein of unknown function, YhdP, and deletion of
yhdP
damages the OM permeability barrier in a cyclic ECA-dependent manner, allowing harmful molecules such as antibiotics into the cell. This role in maintenance of the envelope permeability barrier is the first time a phenotype has been described for cyclic ECA. As the Gram-negative envelope is generally impermeable to antibiotics, understanding the mechanisms through which the barrier is maintained and antibiotics are excluded may lead to improved antibiotic delivery.
Investigating the Campylobacter jejuni Transcriptional Response to Host Intestinal Extracts Reveals the Involvement of a Widely Conserved Iron Uptake System
Authors: Liu Martha M. , Boinett Christine J. , Chan Anson C. K. , Parkhill Julian , Murphy Michael E. P. , Gaynor Erin C.
Published: August 2018

Campylobacter jejuniis a pathogenic bacterium that causes gastroenteritis in humans yet is a widespread commensal in wild and domestic animals, particularly poultry. Using RNA sequencing, we assessedC. jejunitranscriptional responses to medium supplemented with human fecal versus chicken cecal extracts and in extract-supplemented medium versus medium alone.C. jejuniexposed to extracts had altered expression of 40 genes related to iron uptake, metabolism, chemotaxis, energy production, and osmotic stress response. In human fecal versus chicken cecal extracts,C. jejunidisplayed higher expression of genes involved in respiration (fdhTU) and in known or putative iron uptake systems (cfbpA,ceuB,chuC, andCJJ81176_1649–1655[here designated1649–1655]). The1649–1655genes and downstream overlapping gene1656were investigated further. Uncharacterized homologues of this system were identified in 33 diverse bacterial species representing 6 different phyla, 21 of which are associated with human disease. The1649and1650(p19) genes encode an iron transporter and a periplasmic iron binding protein, respectively; however, the role of the downstream1651–1656genes was unknown. A Δ1651–1656deletion strain had an iron-sensitive phenotype, consistent with a previously characterized Δp19mutant, and showed reduced growth in acidic medium, increased sensitivity to streptomycin, and higher resistance to H2O2stress. In iron-restricted medium, the1651–1656andp19genes were required for optimal growth when using human fecal extracts as an iron source. Collectively, this implicates a function for the1649–1656gene cluster inC. jejuniiron scavenging and stress survival in the human intestinal environment.

IMPORTANCEDirect comparative studies ofC. jejuniinfection of a zoonotic commensal host and a disease-susceptible host are crucial to understanding the causes of infection outcome in humans. These studies are hampered by the lack of a disease-susceptible animal model reliably displaying a similar pathology to human campylobacteriosis. In this work, we compared the phenotypic and transcriptional responses ofC. jejunito intestinal compositions of humans (disease-susceptible host) and chickens (zoonotic host) by using human fecal and chicken cecal extracts. The mammalian gut is a complex and dynamic system containing thousands of metabolites that contribute to host health and modulate pathogen activity. We identifiedC. jejunigenes more highly expressed during exposure to human fecal extracts in comparison to chicken cecal extracts and differentially expressed in extracts compared with medium alone, and targeted one specific iron uptake system for further molecular, genetic, and phenotypic study.
Azithromycin Resistance through Interspecific Acquisition of an Epistasis-Dependent Efflux Pump Component and Transcriptional Regulator in Neisseria gonorrhoeae
Authors: Wadsworth Crista B. , Arnold Brian J. , Sater Mohamad R. Abdul , Grad Yonatan H.
Published: August 2018

Mosaic interspecifically acquired alleles of the multiple transferable resistance (
mtr
) efflux pump operon correlate with increased resistance to azithromycin in
Neisseria gonorrhoeae
in epidemiological studies. However, whether and how these alleles cause resistance is unclear. Here, we use population genomics, transformations, and transcriptional analyses to dissect the relationship between variant
mtr
alleles and azithromycin resistance. We find that the locus encompassing the
mtrR
transcriptional repressor and the
mtrCDE
pump is a hot spot of interspecific recombination introducing alleles from
Neisseria meningitidis
and
Neisseria lactamica
into
N. gonorrhoeae
, with multiple rare haplotypes in linkage disequilibrium at
mtrD
and the
mtr
promoter region. Transformations demonstrate that resistance to azithromycin, as well as to other antimicrobial compounds such as polymyxin B and crystal violet, is mediated through epistasis between these two loci and that the full-length mosaic
mtrD
allele is required. Gene expression profiling reveals the mechanism of resistance in mosaics couples novel
mtrD
alleles with promoter mutations that increase expression of the pump. Overall, our results demonstrate that epistatic interactions at
mtr
gained from multiple neisserial species has contributed to increased gonococcal resistance to diverse antimicrobial agents.

IMPORTANCE
Neisseria gonorrhoeae
is the sexually transmitted bacterial pathogen responsible for more than 100 million cases of gonorrhea worldwide each year. The incidence of resistance to the macrolide azithromycin has increased in the past decade; however, a large proportion of the genetic basis of resistance remains unexplained. This study is the first to conclusively demonstrate the acquisition of macrolide resistance through
mtr
alleles from other
Neisseria
species, demonstrating that commensal
Neisseria
bacteria are a reservoir for antibiotic resistance to macrolides, extending the role of interspecies mosaicism in resistance beyond what has been previously described for cephalosporins. Ultimately, our results emphasize that future fine-mapping of genome-wide interspecies mosaicism may be valuable in understanding the pathways to antimicrobial resistance. Our results also have implications for diagnostics and public health surveillance and control, as they can be used to inform the development of sequence-based tools to monitor and control the spread of antibiotic-resistant gonorrhea.
Identification of Two Regulators of Virulence That Are Conserved in
Klebsiella pneumoniae
Classical and Hypervirulent Strains
Authors: Palacios Michelle , Miner Taryn A. , Frederick Daniel R. , Sepulveda Victoria E. , Quinn Joshua D. , Walker Kimberly A. , Miller Virginia L.
Published: August 2018

Klebsiella pneumoniae
is widely recognized as a pathogen with a propensity for acquiring antibiotic resistance. It is capable of causing a range of hospital-acquired infections (urinary tract infections [UTI], pneumonia, sepsis) and community-acquired invasive infections. The genetic heterogeneity of
K. pneumoniae
isolates complicates our ability to understand the virulence of
K. pneumoniae
. Characterization of virulence factors conserved between strains as well as strain-specific factors will improve our understanding of this important pathogen. The MarR family of regulatory proteins is widely distributed in bacteria and regulates cellular processes such as antibiotic resistance and the expression of virulence factors.
Klebsiella
encodes numerous MarR-like proteins, and they likely contribute to the ability of
K. pneumoniae
to respond to and survive under a wide variety of environmental conditions, including those present in the human body. We tested loss-of-function mutations in all the
marR
homologues in a murine pneumonia model and found that two (
kvrA
and
kvrB
) significantly impacted the virulence of K1 and K2 capsule type hypervirulent (
hv
) strains and that
kvrA
affected the virulence of a sequence type 258 (ST258) classical strain. In the
hv
strains,
kvrA
and
kvrB
mutants displayed phenotypes associated with reduced capsule production, mucoviscosity, and transcription from
galF
and
manC
promoters that drive expression of capsule synthesis genes. In contrast,
kvrA
and
kvrB
mutants in the ST258 strain had no effect on capsule gene expression or capsule-related phenotypes. Thus, KvrA and KvrB affect virulence in classical and
hv
strains but the effect on virulence may not be exclusively due to effects on capsule production.

IMPORTANCE
In addition to having a reputation as the causative agent for hospital-acquired infections as well as community-acquired invasive infections,
Klebsiella pneumoniae
has gained widespread attention as a pathogen with a propensity for acquiring antibiotic resistance. Due to the rapid emergence of carbapenem resistance among
K. pneumoniae
strains, a better understanding of virulence mechanisms and identification of new potential drug targets are needed. This study identified two novel regulators (KvrA and KvrB) of virulence in
K. pneumoniae
and demonstrated that their effect on virulence in invasive strains is likely due in part to effects on capsule production (a major virulence determinant) and hypermucoviscosity. KvrA also impacts the virulence of classical strains but does not appear to affect capsule gene expression in this strain. KvrA and KvrB are conserved among
K. pneumoniae
strains and thus could regulate capsule expression and virulence in diverse strains regardless of capsule type.
Improvement in psychiatric symptoms after strabismus surgery in adolescent patients in long-term follow-up
Authors: Ozates Serdar , Ezerbolat Ozates Melike , Can Cigdem Ulku , Polat Sibel , Yasar Hakan Halit , Taskale Busra , Gogus Ali Kemal
Published: August 2018

Aims

To assess the psychological effects of preoperative primary eye position and surgical correction of strabismus in adolescent patients.

Methods

Eighty-three adolescent patients with exotropia were included in this observational and prospective study. Patients with preoperative manifest exotropia formed the manifest exotropia group. Patients with intermittent exotropia that had orthophoria with overcorrecting minus lenses and recently increased frequency of manifest phase were indicated for surgery and formed the latent deviation group. All patients were scored with the Turkish version of the Social Appearance Anxiety Scale (SAAS), depression subscale of Hospital Anxiety and Depression Scale (HAD-D) Brief Fear of Negative Evaluation Scale (BFNE), state anxiety subscale of State-Trait Anxiety Inventory (STAI-S) and trait anxiety subscale of State-Trait Anxiety Inventory (STAI-T) before and 1 year after strabismus surgery.

Results

The mean preoperative scores of the HAD-D, SAAS, BFNE, STAI-S and STAI-T before strabismus surgery were significantly higher in the manifest exotropia group than in the latent deviation group (p≤0.001 for all). Surgical correction significantly improved the outcomes of all scales in the manifest exotropia group (p≤0.001 for all). Outcomes of the STAI-S and STAI-T significantly improved in the latent deviation group after the surgery (p=0.008, p=0.006, respectively), whereas outcomes of the HAD-D, SAAS and BFNE did not improve (p=0.079, p=0.071, p=0.127, respectively). The mean postoperative scores of all scales did not differ between the two groups (p>0.05 for all).

Conclusions

Strabismus has psychological consequences in adolescent patients, and the visible eye deviation caused by strabismus is a strong indicator of psychological distress.
Cancer patients’ organisation participation in heath policy decision-making: a snapshot/cluster analysis of the EU-28 countries
Authors: Souliotis Kyriakos , Peppou Lily-Evangelia , Tzavara Chara , Agapidaki Eirini , Varvaras Dimitrios , Buonomo Oreste , Debiais Dominique , Hasurdjiev Stanimir , Sarkozy Francois
Published: August 2018

Objectives

Even though patient involvement in health policy decision-making is well documented, studies evaluating the degree and impact of this participation are scarce. This is even more conspicuous in the case of cancer. There is evidence showing that patients with the same type of cancer and at the same stage of the disease will receive different treatments in different countries. Therefore, it is crucial to assess the degree of patient participation in health policy decision-making across Europe, as it may result in health inequalities across countries. In a response to this research call, the present study aimed to provide a snapshot of cancer patients’ organisation (CPO) participation in health policy processes in European Union (EU)-28 countries.

Setting

CPOs from the EU-28 countries.

Participants

Primary and secondary outcome measures: information about participants’ sociodemographic characteristics and their involvement in their CPO was collected as well as data about the CPO. A 17-item index containing questions about the type and impact of participation in various facets of health policy decision-making was used to assess the degree of CPOs participation in health policy decision-making processes and its impact.
Single-arm, open-label, dose-escalation phase I study to evaluate the safety of a herbal medicine SH003 in patients with solid cancer: a study protocol
Authors: Cheon Chunhoo , Kang Sohyeon , Ko Youme , Kim Mia , Jang Bo-Hyoung , Shin Yong-Cheol , Ko Seong-Gyu
Published: August 2018

Introduction

Cancer is a major health problem worldwide and the leading cause of death in many countries. The number of patients with cancer and socioeconomic costs of cancer continues to increase. SH003 is a novel herbal medicine consisting ofAstragalus membranaceus,Angelica gigasandTrichosanthes Kirilowii Maximowicz. Preclinical studies have shown that SH003 has therapeutic anticancer effects. The aim of this study is to determine the maximum tolerated dose of SH003 in patients with solid cancers.

Methods and analysis

This study is an open-label, dose-escalation trial evaluating the safety and tolerability of SH003. The traditional 3+3 dose-escalation design will be implemented. Patients with solid cancers will be recruited. According to dose level, the patients will receive one to four tablets of SH003, three times a day for 3 weeks. Toxicity will be evaluated using common terminology criteria for adverse events (CTCAE). Dose-limiting toxicities are defined as grade 3 or higher adverse events based on CTCAE. The maximum tolerated dose will be determined by the highest dose at which no more than one of six patients experiences dose-limiting toxicity.

Ethics and dissemination

This study has been approved by the institutional review board of the Ajou University Hospital (reference AJIRB-MED-CT1-16-311). The results of this study will be disseminated through a scientific journal and a conference.

Trial registration number

NCT03081819; Pre-results.
Examining ‘institutional entrepreneurship’ in healthcare redesign and improvement through comparative case study research: a study protocol
Authors: Melder Angela , Burns Prue , Mcloughlin Ian , Teede Helena
Published: August 2018

Introduction

Healthcare service redesign and improvement has become an important activity that health system leaders and clinicians realise must be nurtured and mastered, if the capacity issues that constrain healthcare delivery are to be solved. However, little is known about the critical success factors that are essential for sustaining and scaling up improvement initiatives. This situation limits the impact of these initiatives and undermines the general standing of redesign and improvement activity within healthcare systems. The conduct of the doctoral research detailed in this study protocol will be nested within a broader parent study that seeks to address this problem by drawing on the theory of ‘institutional entrepreneurship’. The doctoral research will apply this idea to understanding the capacities and capabilities required at the organisation level to bring about transformational change in healthcare services.

Methods and analysis

The parent study is predominantly qualitative, is multilevel in nature and has been codesigned with five partner healthcare organisations. The focus is a sector-wide attempt in an Australian state jurisdiction to transfer new redesign and improvement knowledge into the public healthcare system. The doctoral research will focus on the implementation of the sector-wide approach in one healthcare service in the jurisdiction. This research involves interviews with project team members and stakeholders involved in two improvement initiatives undertaken by the health service. It will involve interviews with redesign and improvement leaders and senior managers responsible for the overall health service improvement approach. The methods will also include immersive fieldwork, interviews and focus groups. Appropriate methods for coding and thematic extraction will be applied to the qualitative data.

Ethics and dissemination

Ethical approval has been granted by the health service and Monash University Human Research Ethics Committee. Dissemination will be facilitated via academic publication, industry reports and workshops and dissemination events as part of the broader project.
Caesarean sections and the prevalence of preterm and early-term births in Brazil: secondary analyses of national birth registration
Authors: Barros Fernando C , Rabello Neto Dacio de Lyra , Villar Jose , Kennedy Stephen H , Silveira Mariangela F , Diaz-Rossello Jose Luis , Victora Cesar G
Published: August 2018

Objectives

To investigate whether the high rates of caesarean sections (CSs) in Brazil have impacted on the prevalence of preterm and early-term births.

Design

Individual-level, cross-sectional analyses of a national database.

Setting

All hospital births occurring in the country in 2015.

Participants

2 903 716 hospital-delivered singletons in 3157 municipalities, representing >96% of the country’s births.

Primary and secondary outcome measures

CS rates and gestational age distribution (<37, 37–38, 39–41 and 42 or more weeks’ gestation). Outcomes were analysed according to maternal education, measured in years of schooling and municipal CS rates. Analyses were also adjusted for maternal age, marital status and parity.

Results

Prevalence of CS was 55.5%, preterm prevalence (<37 weeks’ gestation) was 10.1% and early-term births (37–38 weeks of gestation) represented 29.8% of all births, ranging from 24.9% among women with <4 years of schooling to 39.8% among those with >12 years of education. The adjusted prevalence ratios of preterm and early-term birth were, respectively, 1.215 (1.174–1.257) and 1.643 (1.616–1.671) higher in municipalities with≥80% CS compared with those <30%.

Conclusions

Brazil faces three inter-related epidemics: a CS epidemic; an epidemic of early-term births, associated with the high CS rates; and an epidemic of preterm birth, also associated with CS but mostly linked to poverty-related risk factors. The high rates of preterm and early-term births produce an excess of newborns at higher risk of short-term morbidity and mortality, as well as long-term developmental problems. Compared with high-income countries, there is an annual excess of 354 000 preterm and early-term births in Brazil.
Development of a core outcome set for immunomodulation in pregnancy (COSIMPREG): a protocol for a systematic review and Delphi study
Authors: Prins Jelmer R , Holvast Floor , van ’t Hooft Janneke , Bos Arend F , Ganzevoort Jan Willem , Scherjon Sicco A , Robertson Sarah A , Gordijn Sanne J
Published: August 2018

Introduction

To establish pregnancy, the maternal immune system must adapt to tolerate the semiallogenic fetus. Less than optimal adaptation of the maternal immune system during (early) pregnancy is implicated in several complications of pregnancy. The development of effective immune modulation interventions as preventive or therapeutic strategies for pregnancy complications holds promise. Several studies sought to evaluate the safety and effectiveness of various approaches. However, a limitation is the high variability in clinical and immune outcomes that are reported. We, therefore, aim to develop a core outcome set for application to studies of immune modulation in pregnancy (COSIMPREG).

Methods and analysis

We will use a stepwise approach to develop a COSIMPREG. First, we will perform a systematic review to identify reported outcomes. For this review, Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines will be followed. Second, we will use the Delphi method to develop a preliminary COSIMPREG. In three rounds, the outcomes of the systematic review will be scored. A panel comprising experts from relevant disciplines and diverse geographical locations will be assembled until a sufficient quality of the panel is reached. We will use predefined decision rules for outcomes. After each round outcomes, including scores, will be returned to the panel for further refinement. The outcomes not excluded after the third round will be taken to a consensus meeting. In this meeting, experts from all relevant disciplines will discuss and finalise the COSIMPREG.

Ethics and dissemination

For this study ethical approval is not required. The systematic review will be published in an appropriate open access reproductive immunology journal. Once the COSIMPREG is finalised, it will be published in an open access reproductive immunology journal, and disseminated at appropriate international meetings, as well as through relevant research and scientific societies. Experts involved in the Delphi study will be asked to give informed consent.
Clinicians’ views on treatment adaptations for men with eating disorders: a qualitative study
Authors: Kinnaird Emma , Norton Caroline , Tchanturia Kate
Published: August 2018

Objectives

Despite traditional views of eating disorders as a female illness, there is a growing body of evidence that the incidence rate of eating disorders in men is rising. Research suggests that these men may experience unique symptoms and difficulties, however, it is unclear how these unique needs may impact treatment. The aim of this study was to explore clinicians’ views on whether men have gender-specific treatment needs, and how far these needs require treatment adaptations.

Design

Qualitative interview study using framework analysis to explore the experiences of clinicians working with men with eating disorders.

Setting

Outpatient National Health Service eating disorder service in London.

Participants

Ten clinicians from a variety of clinical backgrounds participated in the study.

Results

The following three themes emerged: male-specific issues identified by clinicians, treatment approaches used for this population and the importance of creating a male-friendly environment. Male-specific issues identified by participants included an increased focus on muscularity and difficulty expressing or discussing emotion. Clinicians also suggested that men may be more likely to adopt a performance-based approach to. This was linked by clinicians to the impact of cultural perceptions of masculinity on their patients. Clinicians in this study felt that these individual needs could be met by adapting existing approaches within a supportive, male-friendly environment. However, there was not consensus over specific adaptations, including identifying risk, the need for male-only groups, or whether male patients needed access to male clinicians.

Conclusions

Although men do present with specific treatment needs, these can typically be met within the framework of typical treatment approaches by experienced clinicians in an environment sensitive to the presence of men in an otherwise female-dominated space. However, there are a lack of explicit guidelines for this process, and areas such as male-only treatment spaces require further research.
Standard reference values of the upper body posture in healthy young female adults in Germany: an observational study
Authors: Ohlendorf Daniela , Fisch Vanessa , Doerry Charlotte , Schamberger Sebastian , Oremek Gerhard , Ackermann Hanns , Schulze Johannes
Published: August 2018

Objective

Classifications of posture deviations are only possible compared with standard values. However, standard values have been published for healthy male adults but not for female adults.

Design

Observational study.

Setting

Institute of Occupational Medicine, Social Medicine and Environmental Medicine, Goethe-University Frankfurt/Main.

Participants

106healthy female volunteers (21–30 years old; 25.1±2.7 years) were included. Their body weight ranged from 46 to 106 kg (60.3±7.9 kg), the heights from 1.53 to 1.82 m (1.69±0.06 m) and the body mass index from 16.9 kg/m² to 37.6 kg/m² (21.1±2.6 kg/m²).

Outcome measures

A three-dimensional back scan was performed to measure the upper back posture in habitual standing. The tolerance ranges and CI were calculated. Group differences were tested by the Wilcoxon Mann-Whitney U test.

Results

In normal posture, the spinal column was marginally twisted to the left, and the vertebrae were marginally rotated to the right. The kyphosis angle is larger than the lumbar angle. Consequently, a more kyphotic posture is observed in the sagittal plane. The habitual posture is slightly scoliotic with a rotational component (scapular depression right, right scapula marginally more dorsally, high state of pelvic right, iliac right further rotated anteriorly).

Conclusions

Healthy young women have an almost ideally balanced posture with minimal ventral body inclination and a marginal scoliotic deviation. Compared with young males, women show only marginal differences in the upper body posture. These values allow a comparison to other studies, both for control and patient data, and may serve as guideline in both clinical practice and scientific studies.
Use of online promotion to encourage patient awareness of aspirin use to prevent heart attack and stroke
Authors: Southwell Brian G , Eder Milton , Finnegan John , Hirsch Alan T , Luepker Russell V , Duval Sue , Russell Carol , O’Byrne Sam
Published: August 2018

Background

Literature on health promotion evaluation and public understanding of health suggests the importance of investigating behaviour over time in conjunction with information environment trends as a way of understanding programme impact. We analysed population response to online promotion of an educational tool built by the Ask About Aspirin campaign in the USA to inform people about aspirin as a preventive aid.

Methods

We collected 156 weeks of time series data on audience behaviour, namely use of a self-assessment tool. We then used the Autoregressive Integrated Moving Average (ARIMA) modelling to predict that outcome as a function of paid search engine advertising, paid social media promotion and general search interest in aspirin.

Results

Through ARIMA modelling of tool engagement data adjusted for outcome series autocorrelation, we found a significant effect of online promotional effort on audience behaviour. Total paid search advertising positively predicted weekly total of individuals who started using the self-assessment tool, coefficient=0.023, t=3.28, p=0.001. This effect did not appear to be an artefact of broader secular trends, as Google search data on the topic of aspirin use did not add explanatory power in the final model nor did controlling for general search interest eliminate the significant coefficient for paid search promotion.

Conclusion

Results hold implications both for educational tool development and for understanding health promotion campaign effects. We witnessed substantial but ephemeral effects on tool use as a function of paid search efforts, suggesting prioritisation of efforts to affect search engine results as a dissemination tactic.
Mother’s education and late-life disparities in memory and dementia risk among US military veterans and non-veterans
Authors: Vable Anusha M , Eng Chloe W , Mayeda Elizabeth Rose , Basu Sanjay , Marden Jessica R , Hamad Rita , Glymour M Maria
Published: August 2018

Background

Adverse childhood socioeconomic status (cSES) predicts higher late-life risk of memory loss and dementia. Veterans of U.S. wars are eligible for educational and economic benefits that may offset cSES disadvantage. We test whether cSES disparities in late-life memory and dementia are smaller among veterans than non-veterans.

Methods

Data came from US-born men in the 1995–2014 biennial surveys of the Health and Retirement Study (n=7916 born 1928–1956, contributing n=38 381 cognitive assessments). Childhood SES was represented by maternal education. Memory and dementia risk were assessed with brief neuropsychological assessments and proxy reports. Military service (veteran/non-veteran) was evaluated as a modifier of the effect of maternal education on memory and dementia risk. We employed linear or logistic regression models to test whether military service modified the effect of maternal education on memory or dementia risk, adjusted for age, race, birthplace and childhood health.

Results

Low maternal education was associated with worse memory than high maternal education (β = −0.07 SD, 95% CI −0.08 to –0.05), while veterans had better memory than non-veterans (β = 0.03 SD, 95% CI 0.02 to 0.04). In interaction analyses, maternal education disparities in memory were smaller among veterans than non-veterans (difference in disparities = 0.04 SD, 95% CI 0.01 to 0.08, p = 0.006). Patterns were similar for dementia risk.

Conclusions

Disparities in memory by maternal education were smaller among veterans than non-veterans, suggesting military service and benefits partially offset the deleterious effects of low maternal education on late-life cognitive outcomes.
A study of modified holographic Ricci dark energy in the framework of f(T) modified gravity and its statefinder hierarchy
Authors: Majumdar Arkaprabha , Chattopadhyay Surajit
Published: August 2018

Inspired by the work of Bamba et al. (Phys. Rev. D, 85, 104036 (2012)) the present paper reports a study on the reconstruction of modified holographic Ricci dark energy (MHRDE) in the framework of modified gravity taken as f(T) gravity. A correspondence between modified Chaplygin gas and MHRDE has also been considered and thereinafter the f(T) gravity has been reconstructed via reconstruction of the Hubble parameter. The reconstructed equation of state (EoS) parameter obtained this way has been found to be able to cross the phantom boundary. In the next phase of the work, a viable model of f(T) gravity has been considered and MHRDE has been discussed in this modified gravity frame. The EoS parameter due to the torsion contribution obtained this way has been found to behave like quintessence. The transition of the universe from the dark matter dominated to dark energy (DE) dominated phase is apparent from this model. Also, the model is exhibiting DE domination of the current universe. Finally, the statefinder hierarchy has been discussed through the statefinder and snap parameters. The model has been found to be able to attain the ΛCDM fixed point in the statefinder trajectory.
An Accurate Illumination Model of Machined Surface Based on Micro-Image
Authors: Shi Weichao , Zheng Jianming , Li Yan , Li Xubo , An Qiannan
Published: August 2018

This paper focused on the illumination model of machined surface based on micro-image. According to micro-image forming condition, the theory that the image brightness is related to the microfacet topography and surface reflection characteristics is presented. The distribution rule of micro-topography and reflection characteristics of sample surface is analyzed according to the measured data. An illumination mode of machined surface is established based on the analysis result, and the model parameters are obtained by using the simulated annealing algorithm. Verification results show that this proposed model can improve the simulation accuracy significantly and describe the lighting effect of machined surface. The research will provide a new idea and method for the 3D reconstruction.
A Research on the Optimal Design of BP Neural Network Based on Improved GEP
Authors: Wang Ruliang , Zha Benbo
Published: August 2018

Due to the functionality of dynamic mapping for nonlinear complex data, BP neural network (BP-NN) as a typical neural network has increasingly been applied to a variety of applications. Although it has been successfully applied, its prominent shortcoming, such as the local optimum problem and the setting problem for the initial parameter of neural network, have not been completely eliminated. In this paper, an optimization algorithm for the architecture, weights and thresholds of neural networks using an improved gene expression programming (IGEP) was presented. The algorithm effectively combines the global search ability of GEP and the local search ability of BP-NN. To obtain a better efficiency, the basic GEP was improved by the dynamic adjustment of the fitness function, genetic operators and the number of evolutionary generations. The experimental results show that the IGEP-BP algorithm is an effective method for evolving neural network.
Transfer Learning Based on Regularized Common Spatial Patterns Using Cosine Similarities of Spatial Filters for Motor-Imagery BCI
Authors: Xu Yilu , Wei Qingguo , Zhang Hua , Hu Ronghua , Liu Jizhong , Hua Jing , Guo Fumin
Published: August 2018

In motor-imagery brain–computer interface (BCI), transfer learning based on the framework of regularized common spatial patterns (RCSP) can make full use of the training data derived from other subjects to reduce calibration time for a new subject. Covariance matrices are commonly used to estimate the difference between subjects. However, the classification performances vary greatly depending on different assumptions of the distribution of covariance matrices. Therefore, to directly observe the variations of the target subject’s features after transferring, we neglect the distribution of covariance matrices and instead compare cosine similarities of spatial filters between the target subject and the composite subject whose data comes from the target subject and a source subject. Two RCSP algorithms based on cosine measure are proposed to use the samples of all source subjects and most useful source subjects, respectively. Experiments on one public data set from BCI competition show that our proposed approaches significantly improve the classification performances compared to the conventional CSP algorithm in almost every case, based on a small training set.
PRICING INTEREST RATE DERIVATIVES UNDER MONETARY CHANGES
Authors: DE GENARO ALAN , AVELLANEDA MARCO
Published: August 2018

The goal of this paper is to develop a reduced-form model for pricing derivatives on the overnight rate. The model incorporates jumps around central bank (CB) meetings. More specifically, rate changes are decomposed into fluctuations between CB meetings and deterministic timed jumps following CB meetings. This approach is useful for practitioners, since it allows the extraction of expectations regarding central bank decisions embedded in liquid instruments, as well as the use of these expectations for the pricing of less liquid derivatives, such as options, in a consistent manner. We discuss applications to 30-Day Fed funds options and IDI options traded in Brazil.
Impact of Oil Price on Australian Stock Market Returns
Authors: Li Hui , Paraco Raul
Published: August 2018

We observe a positive correlation between an oil price factor and the All Ordinaries Index of the Australian stock market. Furthermore, an asymmetrical effect is observed when the sample is divided into sub-periods. A more pervasive stock market response is observed when the price of oil displays a positive trend. We also study the influence of oil shocks on the stock returns of specific Australian industries. As expected, the energy and material sectors exhibit a positive response to oil disturbances, whereas the financial and industrial sectors show a negative relation to oil shocks. The utility and consumer discretionary sectors exhibit a lower sensitivity to oil shocks.
Finite Element Formulation for Linear Stability Analysis of Axially Functionally Graded Nonprismatic Timoshenko Beam
Authors: Soltani Masoumeh , Asgarian Behrouz
Published: August 2018

An improved approach based on the power series expansions is proposed to exactly evaluate the static and buckling stiffness matrices for the linear stability analysis of axially functionally graded (AFG) Timoshenko beams with variable cross-section and fixed–free boundary condition. Based on the Timoshenko beam theory, the equilibrium equations are derived in the context of small displacements, considering the coupling between the transverse deflection and angle of rotation. The system of stability equations is then converted into a single homogeneous differential equation in terms of bending rotation for the cantilever, which is solved numerically with the help of the power series approximation. All the mechanical properties and displacement components are thus expanded in terms of the power series of a known degree. Afterwards, the shape functions are gained by altering the deformation shape of the AFG nonprismatic Timoshenko beam in a power series form. At the end, the elastic and buckling stiffness matrices are exactly determined by the weak form of the governing equation. The precision and competency of the present procedure in stability analysis are assessed through several numerical examples of axially nonhomogeneous and homogeneous Timoshenko beams with clamped-free ends. Comparison is also made with results obtained using ANSYS and other solutions available, which indicates the correctness of the present method.
Study on Singular Spectrum Analysis as a New Technical Oscillator for Trading Rules Design
Authors: Leles Michel Carlo Rodrigues , Mozelli Leonardo Amaral , Júnior Cairo Lúcio Nascimento , Sbruzzi Elton Felipe , Guimarães Homero Nogueira
Published: August 2018

The connection between Singular Spectrum Analysis (SSA) decomposition and short-term market movements is investigated. Since SSA is a non-parametric approach, suitable to decompose general time-series into meaningful components, such as trends, oscillations and noise, it is proposed as a new oscillator-type Technical Indicator, replacing popular ones. New Technical Trading Rules (TTRs) are designed and applied to some major global stock indexes to illustrate the benefits in terms of revealing market movements. The performance is evaluated according to different risk-adjustment metrics and the empirical results reveal that the SSA-TTRs may outperform some popular technical oscillators and also the Buy & Hold strategy.
Nonlinear Free Vibration of Spinning Viscoelastic Pipes Conveying Fluid
Authors: Liang Feng , Yang Xiao-Dong , Zhang Wei , Qian Ying-Jing
Published: August 2018

Drill strings are one of the most significant rotor components employed in oil and gas exploitation. In this paper, an improved dynamical model of drill-string-like pipes conveying fluid is developed by taking into account the axial spin, fluid–structure interaction (FSI), damping as well as curvature and inertia nonlinearities. The partial differential equations of motion are derived by two sequential Euler angles and the Hamilton principle and then directly handled by the multiple scales method. The nonlinear amplitudes, frequencies and whirling mode shapes are all investigated towards various system parameters to display the nonlinear dynamical characteristics of such a special rotor system coupled with FSI. It is revealed that the nonlinear amplitudes and frequencies are explicitly dependent on the spinning speed, while the flowing fluid mainly contributes to the linear frequencies, and consequently influences the nonlinear amplitudes and frequencies. The FSI effect and axial spin can both improve the forward procession mode and suppress the backward one, while both procession modes will be suppressed by the viscoelastic damping. The pipe will ultimately present a forward as well as decayed whirling motion for the fundamental mode.
1-Dimensional intrinsic persistence of geodesic spaces
Authors: Virk Žiga
Published: August 2018

Given a compact geodesic space [Formula: see text], we apply the fundamental group and alternatively the first homology group functor to the corresponding Rips or Čech filtration of [Formula: see text] to obtain what we call a persistence object. This paper contains the theory describing such persistence: properties of the set of critical points, their precise relationship to the size of holes, the structure of persistence and the relationship between open and closed, Rips and Čech induced persistences. Amongst other results, we prove that a Rips critical point [Formula: see text] corresponds to an isometrically embedded circle of length [Formula: see text], that a homology persistence of a locally contractible space with coefficients in a field encodes the lengths of the lexicographically smallest base, and that Rips and Čech induced persistences are isomorphic up to a factor [Formula: see text]. The theory describes geometric properties of the underlying space encoded and extractable from persistence.
Limit sets of Weil–Petersson geodesics with nonminimal ending laminations
Authors: Brock Jeffrey , Leininger Christopher , Modami Babak , Rafi Kasra
Published: August 2018

In this paper, we construct examples of Weil–Petersson geodesics with nonminimal ending laminations which have [Formula: see text]-dimensional limit sets in the Thurston compactification of Teichmüller space.
Freeness of the random fundamental group
Authors: Newman Andrew
Published: August 2018

Let [Formula: see text] denote the probability space of random 2-dimensional simplicial complexes in the Linial–Meshulam model, and let [Formula: see text] denote a random complex chosen according to this distribution. In a paper of Cohen, Costa, Farber and Kappeler, it is shown that for [Formula: see text] with high probability [Formula: see text] is free. Following that, a paper of Costa and Farber shows that for values of [Formula: see text] which satisfy [Formula: see text] with high probability, [Formula: see text] is not free. Here, we improve on both these results to show that there are explicit constants [Formula: see text], so that for [Formula: see text] with high probability [Formula: see text] has free fundamental group and that for [Formula: see text] with high probability [Formula: see text] has fundamental group which either is not free or is trivial.