bluuebunny/crossref_metadata_2025 huggingface dataset:
Osmotic water transport in aquaporins: evidence for a stochastic mechanism
Authors: Zeuthen Thomas , Alsterfjord Magnus , Beitz Eric , MacAulay Nanna
Published: August 2013

Key points

We test a novel model of osmosis in aquaporins.

A solute molecule present at the pore mouth can be reflected or permeate the pore; we propose that only reflected molecules induce osmotic water transport, while permeating molecules give rise to no water transport.

We tested a range of channel geometries using aquaporins AQP1 and AQP9 and mutants thereof; the aquaporins were expressed in Xenopus oocytes. Osmotic gradients were generated by solutes of molecular weights in the range 45–595 Daltons. The reflected fraction of a given solute was estimated optically and compared to the permeability obtained from uptakes of radio‐labelled solutes.

In accordance with our model there was a linear relationship between solute permeability and reflection coefficient: solutes with high permeability had low reflection coefficients and vice versa.

We found no evidence for significant coupling between water and solute fluxes inside the pore.

Abstract  We test a novel, stochastic model of osmotic water transport in aquaporins. A solute molecule present at the pore mouth can either be reflected or permeate the pore. We assume that only reflected solute molecules induce osmotic transport of water through the pore, while permeating solute molecules give rise to no water transport. Accordingly, the rate of water transport is proportional to the reflection coefficient σ, while the solute permeability, PS, is proportional to 1 –σ. The model was tested in aquaporins heterologously expressed in Xenopus oocytes. A variety of aquaporin channel sizes and geometries were obtained with the two aquaporins AQP1 and AQP9 and mutant versions of these. Osmotic water transport was generated by adding 20 mm of a range of different‐sized osmolytes to the outer solution. The osmotic water permeability and the reflection coefficient were measured optically at high resolution and compared to the solute permeability obtained from short‐term uptake of radio‐labelled solute under isotonic conditions. For each type of aquaporin there was a linear relationship between solute permeability and reflection coefficient, in accordance with the model. We found no evidence for coupling between water and solute fluxes in the pore. In confirmation of molecular dynamic simulations, we conclude that the magnitude of the osmotic water permeability and the reflection coefficient are determined by processes at the arginine selectivity filter located at the outward‐facing end of the pore.
Antimicrobial Susceptibility Pattern and Epidemiology of Female Urinary Tract Infections in South Korea, 2010-2011
Authors: Lee Dong Sup , Choe Hyun-Sop , Lee Sung Jong , Bae Woong Jin , Cho Hyeong Jun , Yoon Byung Il , Cho Yong-Hyun , Han Chang Hee , Jang Hoon , Park Su Bum , Cho Won Jin , Lee Seung-Ju
Published: August 2013

This study aimed to (i) investigate the antimicrobial susceptibilities of bacteria that cause urinary tract infections (UTIs) in outpatient and inpatient settings and (ii) evaluate the risk factors for emerging antimicrobial drug resistance in UTIs in South Korea. In total, 3,023 samples without duplication were collected from females between 25 and 65 years of age who had been diagnosed with a urinary tract infection. Multicenter patient data were collected using a Web-based electronic system and then evaluated. The isolation rates of
Escherichia coli
,
Klebsiella pneumoniae
, and
Enterococcus faecium
in the outpatient setting were 78.1, 4.7, and 1.3%, respectively; in the inpatient setting, the isolation rates of these microorganisms were 37.8, 9.9, and 14.8%, respectively. The susceptibilities of
E. coli
to amikacin, amoxicillin-clavulanic acid, cefotaxime, cefoxitin, ciprofloxacin, piperacillin-tazobactam, and imipenem in the outpatient setting were 99.4, 79.8, 89.4, 92.8, 69.8, 96.9, and 100.0%, respectively; in the inpatient setting, the susceptibilities to these antibiotics were 97.8, 73.9, 73.7, 82.1, 53.6, 93.2, and 100.0%, respectively. The most unique and common risk factor for emerging antimicrobial-resistant
E. coli
,
K. pneumoniae
, and
E. faecium
was previous exposure to antimicrobials. On the basis of these data, the use of fluoroquinolones should be reserved until culture data are available for the treatment of UTIs in South Korea. The present study will serve as a useful reference for Far Eastern Asia.
Improving the Lethal Effect of Cpl-7, a Pneumococcal Phage Lysozyme with Broad Bactericidal Activity, by Inverting the Net Charge of Its Cell Wall-Binding Module
Authors: Díez-Martínez Roberto , de Paz Héctor , Bustamante Noemí , García Ernesto , Menéndez Margarita , García Pedro
Published: August 2013

Phage endolysins are murein hydrolases that break the bacterial cell wall to provoke lysis and release of phage progeny. Recently, these enzymes have also been recognized as powerful and specific antibacterial agents when added exogenously. In the pneumococcal system, most cell wall associated murein hydrolases reported so far depend on choline for activity, and Cpl-7 lysozyme constitutes a remarkable exception. Here, we report the improvement of the killing activity of the Cpl-7 endolysin by inversion of the sign of the charge of the cell wall-binding module (from −14.93 to +3.0 at neutral pH). The engineered variant, Cpl-7S, has 15 amino acid substitutions and an improved lytic activity against
Streptococcus pneumoniae
(including multiresistant strains),
Streptococcus pyogenes
, and other pathogens. Moreover, we have demonstrated that a single 25-μg dose of Cpl-7S significantly increased the survival rate of zebrafish embryos infected with
S. pneumoniae
or
S. pyogenes
, confirming the killing effect of Cpl-7S
in vivo
. Interestingly, Cpl-7S, in combination with 0.01% carvacrol (an essential oil), was also found to efficiently kill Gram-negative bacteria such as
Escherichia coli
and
Pseudomonas putida
, an effect not described previously. Our findings provide a strategy to improve the lytic activity of phage endolysins based on facilitating their pass through the negatively charged bacterial envelope, and thereby their interaction with the cell wall target, by modulating the net charge of the cell wall-binding modules.
Adaptation of Enterococcus faecalis to Daptomycin Reveals an Ordered Progression to Resistance
Authors: Miller Corwin , Kong Jiayi , Tran Truc T. , Arias Cesar A. , Saxer Gerda , Shamoo Yousif
Published: August 2013

With increasing numbers of hospital-acquired antibiotic resistant infections each year and staggering health care costs, there is a clear need for new antimicrobial agents, as well as novel strategies to extend their clinical efficacy. While genomic studies have provided a wealth of information about the alleles associated with adaptation to antibiotics, they do not provide essential information about the relative importance of genomic changes, their order of appearance, or potential epistatic relationships between adaptive changes. Here we used quantitative experimental evolution of a single polymorphic population in continuous culture with whole-genome sequencing and allelic frequency measurements to study daptomycin (DAP) resistance in the vancomycin-resistant clinical pathogen
Enterococcus faecalis
S613. Importantly, we sustained both planktonic and nonplanktonic (i.e., biofilm) populations in coculture as the concentration of antibiotic was raised, facilitating the development of more ecological complexity than is typically observed in laboratory evolution. Quantitative experimental evolution revealed a clear order and hierarchy of genetic changes leading to resistance, the signaling and metabolic pathways responsible, and the relative importance of these mutations to the evolution of DAP resistance. Despite the relative simplicity of this
ex vivo
approach compared to the ecological complexity of the human body, we showed that experimental evolution allows for rapid identification of clinically relevant adaptive molecular pathways and new targets for drug design in pathogens.
Role of Yersinia pestis Toxin Complex Family Proteins in Resistance to Phagocytosis by Polymorphonuclear Leukocytes
Authors: Spinner Justin L. , Carmody Aaron B. , Jarrett Clayton O. , Hinnebusch B. Joseph
Published: August 2013

Yersinia pestis
carries homologues of the toxin complex (Tc) family proteins, which were first identified in other Gram-negative bacteria as having potent insecticidal activity. The
Y. pestis
Tc proteins are neither toxic to fleas nor essential for survival of the bacterium in the flea, even though
tc
gene expression is highly upregulated and much more of the Tc proteins YitA and YipA are produced in the flea than when
Y. pestis
is grown
in vitro
. We show that Tc
+
and Tc
−
Y. pestis
strains are transmitted equivalently from coinfected fleas, further demonstrating that the Tc proteins have no discernible role, either positive or negative, in transmission by the flea vector. Tc proteins did, however, confer
Y. pestis
with increased resistance to killing by polymorphonuclear leukocytes (PMNs). Resistance to killing was not the result of decreased PMN viability or increased intracellular survival but instead correlated with a Tc protein-dependent resistance to phagocytosis that was independent of the type III secretion system (T3SS). Correspondingly, we did not detect T3SS-dependent secretion of the native Tc proteins YitA and YipA or the translocation of YitA– or YipA–β-lactamase fusion proteins into CHO-K1 (CHO) cells or human PMNs. Thus, although highly produced by
Y. pestis
within the flea and related to insecticidal toxins, the Tc proteins do not affect interaction with the flea or transmission. Rather, the
Y. pestis
Tc proteins inhibit phagocytosis by mouse PMNs, independent of the T3SS, and may be important for subverting the mammalian innate immune response immediately following transmission from the flea.
Mucosal Vaccination against Tuberculosis Using Inert Bioparticles
Authors: Reljic Rajko , Sibley Laura , Huang Jen-Min , Pepponi Ilaria , Hoppe Andreas , Hong Huynh A. , Cutting Simon M.
Published: August 2013

Needle-free, mucosal immunization is a highly desirable strategy for vaccination against many pathogens, especially those entering through the respiratory mucosa, such as
Mycobacterium tuberculosis
. Unfortunately, mucosal vaccination against tuberculosis (TB) is impeded by a lack of suitable adjuvants and/or delivery platforms that could induce a protective immune response in humans. Here, we report on a novel biotechnological approach for mucosal vaccination against TB that overcomes some of the current limitations. This is achieved by coating protective TB antigens onto the surface of inert bacterial spores, which are then delivered to the respiratory tract. Our data showed that mice immunized nasally with coated spores developed humoral and cellular immune responses and multifunctional T cells and, most importantly, presented significantly reduced bacterial loads in their lungs and spleens following pathogenic challenge. We conclude that this new vaccine delivery platform merits further development as a mucosal vaccine for TB and possibly also other respiratory pathogens.
Hypereosinophilic syndrome secondary to strongyloides infection: a case of recurrent asthma exacerbations
Authors: Khan Waseem Asrar , Santhanakrishnan Karthik
Published: August 2013

Hypereosinophilic syndrome is a disease characterised by a persistently elevated eosinophil count. The syndrome can be reactive to infections, autoimmune disease, cancers, etc. Multiple organ involvement can occur including cardiomyopathies, pulmonary involvement and neuropathies. We describe a case of a patient who presented with signs and symptoms of asthma with recurrent asthma exacerbations, but in fact proved to be hypereosinophilic syndrome secondary to strongyloides infection.
Coinfection of pulmonary mucormycosis and aspergillosis presenting as bilateral vocal cord palsy
Authors: Mahadevaiah Arun H , Rajagopalan Natarajan , Patil Mahantesh , C Shivaprasad
Published: August 2013

Invasive pulmonary coinfection withMucorandAspergillusis rare. Bilateral vocal cord paralysis resulting from coinfection with these two fungi to our knowledge has not been reported in the literature. We report a young woman with diabetes who presented with symptoms of community acquired pneumonia in association with hoarseness of voice. Investigations revealed air space consolidation of the right upper lobe, evidence of mediastinal involvement extending into the paratracheal space and entrapment of right upper lobe pulmonary artery. Bronchoscopy revealed bilateral vocal cord paralysis and sloughing of mucosa of the right upper lobe bronchus and the bronchus intermedius. Microbiological and pathological results confirmedMucorandAspergillus. Extensive vascular and mediastinal involvement precludes surgical debridement. Despite aggressive medical management the patient deteriorated and died of respiratory failure. Strong suspicion of invasive fungal infections in immune compromised patients presenting with unresolving pneumonia and hoarseness of voice, early aggressive treatment is crucial for the patient survival.
Novel psychoactive substances: a novel clinical challenge
Authors: Smith Christopher Daniel , Williams Margaret , Shaikh Maliha
Published: August 2013

The recreational use of novel psychoactive substances in the UK has increased markedly within the last decade. The variety of new substances synthesised and sold as ‘legal’, often under the pretence of being ‘plant food’ or ‘bath salts’ is similarly increasing. This presents challenges to clinicians: they may be unaware of these substances or unable to identify them and their potential for complications and drug interactions. This case describes a patient who ingested a novel psychoactive substance and presented with severe agitation following a delay of several days. He experienced renal, hepatic and neurological complications requiring critical care input. Our case adds to the current repertoire of knowledge regarding the effects of ingestion of novel cathinones.
Road traffic injury mortality and its mechanisms in India: nationally representative mortality survey of 1.1 million homes
Authors: Hsiao Marvin , Malhotra Ajai , Thakur J S , Sheth Jay K , Nathens Avery B , Dhingra Neeraj , Jha Prabhat ,   for the Million Death Study Collaborators
Published: August 2013

Objectives

To quantify and describe the mechanism of road traffic injury (RTI) deaths in India.

Design

We conducted a nationally representative mortality survey where at least two physicians coded each non-medical field staff's verbal autopsy reports. RTI mechanism data were extracted from the narrative section of these reports.

Setting

1.1 million homes in India.

Participants

Over 122 000 deaths at all ages from 2001 to 2003.

Primary and secondary outcome measures

Age-specific and sex-specific mortality rates, place and timing of death, modes of transportation and injuries sustained.

Results

The 2299 RTI deaths in the survey correspond to an estimated 183 600 RTI deaths or about 2% of all deaths in 2005 nationally, of which 65% occurred in men between the ages 15 and 59 years. The age-adjusted mortality rate was greater in men than in women, in urban than in rural areas, and was notably higher than that estimated from the national police records. Pedestrians (68 000), motorcyclists (36 000) and other vulnerable road users (20 000) constituted 68% of RTI deaths (124 000) nationally. Among the study sample, the majority of all RTI deaths occurred at the scene of collision (1005/1733, 58%), within minutes of collision (883/1596, 55%), and/or involved a head injury (691/1124, 62%). Compared to non-pedestrian RTI deaths, about 55 000 (81%) of pedestrian deaths were associated with less education and living in poorer neighbourhoods.

Conclusions

In India, RTIs cause a substantial number of deaths, particularly among pedestrians and other vulnerable road users. Interventions to prevent collisions and reduce injuries might address over half of the RTI deaths. Improved prehospital transport and hospital trauma care might address just over a third of the RTI deaths.
The persistence of adolescent binge drinking into adulthood: findings from a 15-year prospective cohort study
Authors: Degenhardt Louisa , O'Loughlin Christina , Swift Wendy , Romaniuk Helena , Carlin John , Coffey Carolyn , Hall Wayne , Patton George
Published: August 2013

Objectives

To examine the prevalence of binge drinking in adolescence and its persistence into adulthood in an Australian cohort.

Design

15-year prospective cohort study.

Setting

Victoria, Australia.

Participants

1943 adolescents were recruited from secondary schools at age 14–15 years.

Primary outcome measures

Levels of past-week ‘binge’ drinking (5+ standard drinks on a day, each 10 g alcohol) and ‘heavy binge’ drinking (20+ standard drinks on a day for males, 11+ for females) were assessed during six adolescent waves, and across three adult waves up to age 29 years.

Results

Half of the males (52%) and a third of the females (34%) reported past-week adolescent binge drinking. 90% of male and 70% of female adolescent-onset binge drinkers continued to binge in young adulthood; 70% of males and 48% of females who were not adolescent-onset binge drinkers reported young adult binge drinking. Past-week heavy bingeing was less common in adolescence than adulthood. Overall, 35% of the sample (95% CI 33% to 38%) reported past-week binge drinking in adolescence and young adulthood and one-third (33%; 30% to 35%) first reported binge drinking in young adulthood; only 7% of the sample (6–8%) had binge drinking in adolescence but not young adulthood. ‘Heavy binge’ drinking occurred in adolescence and young adulthood for 9% (8% to 10%); 8% (7% to 10%) reported it in adolescence but no longer in young adulthood; and 24% (22% to 26%) began ‘heavy binge’ drinking in young adulthood. Among adolescent binge drinkers (n=821), young adult binge and heavy binge drinking were predicted by being male, adolescent antisocial behaviour and adverse consequences of drinking in adolescence.

Conclusions

Binge alcohol use is common and persistent among young Australians. Efforts to prevent the onset of binge drinking during adolescence may substantially reduce harmful patterns of alcohol use in young adulthood.
Barriers to, and facilitators in, introducing integrated diabetes care in Ireland: a qualitative study of views in general practice
Authors: Mc Hugh Sheena , O'Mullane Monica , Perry Ivan J , Bradley Colin
Published: August 2013

Objective

To examine the barriers to, and facilitators in, improving diabetes management from the general practice perspective, in advance of the implementation of an integrated model of care in Ireland.

Design

Qualitative using semistructured interviews.

Setting

Primary care in the Republic of Ireland.

Participants

Purposive sample of 29 general practitioners (GPs) and two practice nurses.

Methods

Data were analysed using a framework approach.

Results

The main barriers and facilitators occurred at the level of the health system but had a ripple effect at an organisational, professional and patient level. The lack of targeted remuneration for diabetes management in the Irish health system created apathy in general practice and was perceived to be indicative of the lack of value placed on chronic disease management in the health system. There were ‘pockets of interest’ among GPs motivated by ‘vocational’ incentives such as a sense of professional duty; however, this was not sufficient to drive widespread improvement. The hospital service was seen as an essential support for primary care management, although some participants referred to emerging tension between settings. The lack of coordination at the primary–secondary interface resulted in avoidable duplication and an ‘in the meantime’ period of uncertainty around when patients would be called or recalled by specialist services. Facilitators included the availability of nursing support and serendipitous access to services. The lack of resources in the community was considered to be at odds with policy to shift routine management to general practice, which is fast reaching saturation.

Conclusions

At present, intrinsic motivation is driving the improvement of diabetes care in Ireland. This will not be sufficient to implement the proposed reform including a national model of integrated care. Policymakers need to assess and prepare for the disparate levels of interest and infrastructure in primary care in Ireland to support this change.
Do men consult less than women? An analysis of routinely collected UK general practice data
Authors: Wang Yingying , Hunt Kate , Nazareth Irwin , Freemantle Nick , Petersen Irene
Published: August 2013

Objective

To examine whether gender differences in primary care consultation rates (1) vary by age and deprivation status and (2) diminish when consultation for reproductive reasons or common underlying morbidities are accounted for.

Design

Cross-sectional study of a cohort of patients registered with general practice.

Setting

UK primary care.

Subjects

Patients (1 869 149 men and 1 916 898 women) registered with 446 eligible practices in 2010.

Primary outcome measures

Primary care consultation rate.

Results

This study analyses routinely collected primary care consultation data. The crude consultation rate was 32% lower in men than women. The magnitude of gender difference varied across the life course, and there was no ‘excess’ female consulting in early and later life. The greatest gender gap in primary care consultations was seen among those aged between 16 and 60 years. Gender differences in consulting were higher in people from more deprived areas than among those from more affluent areas. Accounting for reproductive-related consultations diminished but did not eradicate the gender gap. However, consultation rates in men and women who had comparable underlying morbidities (as assessed by receipt of medication) were similar; men in receipt of antidepressant medication were only 8% less likely to consult than women in receipt of antidepressant medication (relative risk (RR) 0.916, 95% CI 0.913 to 0.918), and men in receipt of medication to treat cardiovascular disease were just 5% less likely to consult (RR=0.950, 95% CI 0.948 to 0.952) than women receiving similar medication. These small gender differences diminished further, particularly for depression (RR=0.950, 95% CI 0.947 to 0.953), after also taking account of reproductive consultations.

Conclusions

Overall gender differences in consulting are most marked between the ages of 16 and 60 years; these differences are only partially accounted for by consultations for reproductive reasons. Differences in consultation rates between men and women were largely eradicated when comparing men and women in receipt of medication for similar underlying morbidities.
Impact of helicopter emergency medical services in major incidents: systematic literature review
Authors: Johnsen Anne Siri , Fattah Sabina , Sollid Stephen J M , Rehn Marius
Published: August 2013

Introduction

Helicopter emergency medical services (HEMS) aim to bring highly specialised crews to the major incident for triage, treatment and transport. When the site is difficult to access, HEMS may be the only mode of transportation of both personnel and patients. This systematic review will identify, describe and appraise literature regarding the role of HEMS in medical response to major incidents. We aim to improve knowledge on HEMS role in a major incident and provide a basis for future research.

Methods and analysis

A systematic literature review will be conducted with search phrases that combine HEMS and major incidents to identify when and how HEMS have been used. Included literature will be subject to quality appraisal and data extraction.

Ethics

No ethical approval is sought because this is a literature review. It will be submitted to a peer-reviewed journal and the PRISMA guidelines will be followed.

Registration details

PROSPERO CRD42013004473
Pyrethroid poisoning: features and predictors of atypical presentations
Authors: Cha Yong Sung , Kim Hyun , Cho Nam Hyub , Jung Woo Jin , Kim Yong Won , Kim Tae Hoon , Kim Oh Hyun , Cha Kyoung Chul , Lee Kang Hyun , Hwang Sung Oh , Nelson Lewis S
Published: August 2013

Background

Although pyrethroids are known for low toxicity to humans, clinical systemic characteristics of pyrethroid poisoning remain undefined. We investigated atypical presentations of pyrethroid poisoning and the predictors, among those readily assessed in the emergency department.

Methods

59 pyrethroid poisoning cases that were diagnosed and treated at the emergency department of Wonju Severance Christian Hospital from September 2004 to December 2012 were retrospectively reviewed.

Results

Atypical presentations were seen in 22 patients (39.3%). Atypical presentations after pyrethroid poisoning included respiratory failure requiring ventilator care (10 patients, 17.9%), hypotension (systolic blood pressure <90 mm Hg) (6 patients, 10.7%), pneumonia (4 patients, 7.1%), acute kidney injury (6 patients, 10.7%), Glasgow Coma Scale (GCS) <15 (19 patients, 33.9%), seizure (2 patients, 3.6%) and death (2 patients, 3.6%). There were differences between atypical versus typical groups in terms of age (62.1±3.7 vs 51.0±2.9, p=0.020), ingested amounts (300 (IQR 100–338) cc vs 100 (IQR 50–300) cc, p=0.002), and bicarbonate and serum lactate (17.4±1.1 vs 20.5±0.4, p=0.011; and 4.42 (IQR 3.60–7.91) mmol/L vs 3.01 (IQR 2.16–4.73) mmol/L, p=0.010, respectively) in initial arterial blood gas analysis. Predictors of the atypical presentations were ingested amount and serum lactate ((OR 1.004, 95% CI 1.001 to 1.008, p=0.013) and (OR 1.387, CI 1.074 to 1.791, p=0.012), respectively). The optimal points were 250 cc and 3.5 mmol/dL.

Conclusions

39.3% of pyrethroid poisoned patients had atypical presentations with the most common being respiratory failure requiring ventilator care. Predictors of atypical presentation were ingested amount >250 cc and serum lactate >3.5 mmol/L.
Coulomb’s solution to seismic passive earth pressure on retaining walls
Authors: Peng Ming Xiang , Chen Jing
Published: August 2013

The conventional Mononobe–Okabe method is widely used in practice, but is only applicable for calculating total seismic earth pressure of cohesionless soil, not for solving earth pressure distribution. Based on limit equilibrium theory, the backfill is considered to be an ideal elastic–plastic material that obeys the Mohr–Coulomb yield criterion, and a family of slip-lines in the plastic zone is assumed to be a group of straight lines, i.e., planar slip surfaces. Influencing factors including inclination of wall, slope angle of backfill, cohesion and friction angle of soil, adhesion and friction angle between wall and soil, uniform surcharge, and horizontal and vertical seismic coefficients are considered. A more reasonable plastic soil wedge analysis model is established to solve the seismic passive earth pressure on retaining walls, the soil reaction on slip surfaces, and their distributions by using the limit equilibrium method. The geometric and mechanical similarity principle is first proposed by dimensionless analysis. The results show that the total seismic passive earth pressure increases with the algebraic value of the horizontal seismic coefficient, and that it decreases as the algebraic value of the vertical seismic coefficient increases. The present analytical solution is identical to the results in existing literature, and the Mononobe–Okabe method is a special case of this solution.
NATURAL SCALING FOR DARK ENERGY
Authors: GRANDA L. N.
Published: August 2013

We propose a dark energy density based on the Gauss–Bonnet four-dimensional invariant and its modification. This model avoids the necessity of introducing the black hole limit to define the holographic density, since it can be considered as a nonsaturated regime. This allows to describe the dark energy with an equation of state (EoS) and Hubble parameter behaving in a way that can be adjusted very well to recent observations. The model presents quintom behavior without any future fine-time singularities.
THE DYNAMICS OF GEOMETRIC DISCORD AND ITS TRANSFER IN ATOM-CAVITY-RESERVOIR SYSTEM
Authors: WU TAO , SONG XUE-KE , YE LIU
Published: August 2013

The dynamics of geometric discord (GD) and its transfer in a dissipative system consisting of two independent atom-cavity-reservoir subsystems under the strong coupling and the weak coupling regimes is studied. It is shown that the GD of the atoms and the cavities oscillatorily decays to zero while the reservoirs begin to present nonzero geometric quantum discord already immediately after t = 0 in the strong coupling regime. However, in the weak coupling regime, the GD between the atoms progressively decays becoming zero and the discord between the reservoirs arises from zero to a steady value, while the cavities remain almost uncorrelated during the evolution. We also show that the amount of GD contained in atoms and reservoirs depends on the purity p and it is proportional to p, the smaller the value of p the smaller the amount of GD. It is worth noting that, in both strong coupling and the weak coupling regimes, the results show that GD initially stored in the atoms will eventually be completely transferred to the reservoirs, independent of the parameters, but the transfer is mediated via the cavities in the strong coupling regime, while it is almost directly in the weak coupling regime.
VIBRATION OF AXIALLY LOADED AND PARTIALLY INTERACTING COMPOSITE BEAMS
Authors: GRUNDBERG STAFFAN , GIRHAMMAR ULF ARNE , HASSAN OSAMA A. B.
Published: August 2013

The vibrations of axially loaded composite beams with partial interaction are considered. The equations of motion and the pertaining boundary conditions are derived from Hamilton's principle. Mainly free — but also forced — vibrations are considered. The natural frequencies are calculated as a function of the axial force and the stiffness of the interaction between the layers. The analytical result obtained for the eigenfrequencies of the simply supported beam is taken as a starting point for an approximation of the eigenfrequencies of beams subject to other boundary conditions. The proposed approximation — which has no numerical fitting parameters — is shown to be in good agreement with the exact solutions, especially for the case of a beam clamped at both ends.
SIMULATION OF WAVE PROPAGATION OF FLOATING SLAB TRACK-TUNNEL-SOIL SYSTEM BY 2D THEORETICAL MODEL
Authors: ZHOU BIAO , XIE XIONG-YAO , YANG Y. B.
Published: August 2013

Presented herein is a computationally efficient 2D theoretical model for simulating the steady response of a floating slab track-tunnel-soil system. The track-tunnel coupled system is simplified as a beam-spring system and embedded in soil layers. The tunnel is modeled by a Timoshenko beam with its interaction with the soil layers accounted for by two transfer matrices, with each derived for the soil layer above and beneath the tunnel. The approach as proposed herein has been referred to as the Timoshenko beam-transfer matrix method (TTMM), that allows one to analyze the response of the coupled system, including the tunnel motion and soil stresses. The results obtained were compared with those furnished by the pipe-in-pipe (PIP) approach, and were found to be consistent for exciting frequencies smaller than the tunnel second-mode cut-on frequency. The origin of discrepancies was investigated by the dispersion characteristic analysis, which is attributed to the absence of several in-plane modes when the tunnel is simplified as a Timoshenko beam.
CLASSIFICATION OF ARRHYTHMIA IN ELECTROCARDIOGRAM USING EMD BASED FEATURES AND SUPPORT VECTOR MACHINE WITH MARGIN SAMPLING
Authors: SUCHETHA M. , KUMARAVEL N.
Published: August 2013

Electrocardiogram (ECG) signals represent a useful information source about the rhythm and the functioning of the heart. Any disturbance in the heart's normal rhythmic contraction is called an arrhythmia. Analysis of Electrocardiogram signals is the most effective available method for diagnosing cardiac arrhythmias. Computer based classification of ECG provides higher accuracy and offer a potential of an affordable cardiac abnormality mass screening. The empirical mode decomposition is performed on various arrhythmia signals and different levels of intrinsic mode functions (IMF) are obtained. Singular value decomposition (SVD) is used to extract features from the IMF and classification is performed using support vector machine. This method is more efficient for classification of ECG signals and at the same time provides good generalization properties.
INTERFRAME CODING OF CANONICAL PATCHES FOR LOW BIT-RATE MOBILE AUGMENTED REALITY
Authors: MAKAR MINA , TSAI SAM S. , CHANDRASEKHAR VIJAY , CHEN DAVID , GIROD BERND
Published: August 2013

Local features are widely used for content-based image retrieval and augmented reality applications. Typically, feature descriptors are calculated from the gradients of a canonical patch around a repeatable keypoint in the image. In this paper, we propose a temporally coherent keypoint detector and design efficient interframe predictive coding techniques for canonical patches and keypoint locations.

In the proposed system, we strive to transmit each patch with as few bits as possible by simply modifying a previously transmitted patch. This enables server-based mobile augmented reality where a continuous stream of salient information, sufficient for image-based retrieval and localization, can be sent over a wireless link at a low bit-rate. Experimental results show that our technique achieves a similar image matching performance at 1/15 of the bit-rate when compared to detecting keypoints independently frame-by-frame and allows performing streaming mobile augmented reality at low bit-rates of about 20–50 kbps, practical for today's wireless links.
A MAXIMUM ENTROPY BASED DATA-DRIVEN 3D SCENE GENERATION
Authors: DEMA MESFIN A. , SARI-SARRAF HAMED
Published: August 2013

Due to overwhelming use of 3D models in video games and virtual environments, there is a growing interest in 3D scene generation, scene understanding and 3D model retrieval. In this paper, we introduce a data-driven 3D scene generation approach from a Maximum Entropy (MaxEnt) model selection perspective. Using this model selection criterion, new scenes can be sampled by matching a set of contextual constraints that are extracted from training and synthesized scenes. Starting from a set of randomly synthesized configurations of objects in 3D, the MaxEnt distribution is iteratively sampled and updated until the constraints between training and synthesized scenes match, indicating the generation of plausible synthesized 3D scenes. To illustrate the proposed methodology, we use 3D training desk scenes that are composed of seven predefined objects with different position, scale and orientation arrangements. After applying the MaxEnt framework, the synthesized scenes show that the proposed strategy can generate reasonably similar scenes to the training examples without any human supervision during sampling.
POSITIVELY CURVED MANIFOLDS WITH LARGE CONJUGATE RADIUS
Authors: SCHMIDT BENJAMIN
Published: August 2013

Let M denote a complete simply connected Riemannian manifold with all sectional curvatures ≥1. The purpose of this paper is to prove that when M has conjugate radius at least π/2, its injectivity radius and conjugate radius coincide. Metric characterizations of compact rank one symmetric spaces are given as applications.
A Named Entity Recognition Method Based on Decomposition and Concatenation of Word Chunks
Authors: Iwakura Tomoya , Takamura Hiroya , Okumura Manabu
Published: August 2013

We propose a named entity (NE) recognition method in which word chunks are repeatedly decomposed and concatenated. Our method identifies word chunks with a base chunker, such as a noun phrase chunker, and then recognizes NEs from the recognized word chunk sequences. By using word chunks, we can obtain features that cannot be obtained in word-sequence-based recognition methods, such as the first word of a word chunk, the last word of a word chunk, and so on. However, each word chunk may include a part of an NE or multiple NEs. To solve this problem, we use the following operators: SHIFT for separating the first word from a word chunk, POP for separating the last word from a word chunk, JOIN for concatenating two word chunks, and REDUCE for assigning an NE label to a word chunk. We evaluate our method on a Japanese NE recognition dataset that includes about 200,000 annotations of 191 types of NEs from over 8,500 news articles. The experimental results show that the training and processing speeds of our method are faster than those of a linear-chain structured perceptron and a semi-Markov perceptron, while maintaining high accuracy.
Hybrid method based on topography for robust detection of iris center and eye corners
Authors: Villanueva Arantxa , Ponz Victoria , Sesma-Sanchez Laura , Ariz Mikel , Porta Sonia , Cabeza Rafael
Published: August 2013

A multistage procedure to detect eye features is presented. Multiresolution and topographic classification are used to detect the iris center. The eye corner is calculated combining valley detection and eyelid curve extraction. The algorithm is tested in the BioID database and in a proprietary database containing more than 1200 images. The results show that the suggested algorithm is robust and accurate. Regarding the iris center our method obtains the best average behavior for the BioID database compared to other available algorithms. Additional contributions are that our algorithm functions in real time and does not require complex post processing stages.
Towards optimizing human labeling for interactive image tagging
Authors: Tang Jinhui , Chen Qiang , Wang Meng , Yan Shuicheng , Chua Tat-Seng , Jain Ramesh
Published: August 2013

Interactive tagging is an approach that combines human and computer to assign descriptive keywords to image contents in a semi-automatic way. It can avoid the problems in automatic tagging and pure manual tagging by achieving a compromise between tagging performance and manual cost. However, conventional research efforts on interactive tagging mainly focus on sample selection and models for tag prediction. In this work, we investigate interactive tagging from a different aspect. We introduce an interactive image tagging framework that can more fully make use of human's labeling efforts. That means, it can achieve a specified tagging performance by taking less manual labeling effort or achieve better tagging performance with a specified labeling cost. In the framework, hashing is used to enable a quick clustering of image regions and a dynamic multiscale clustering labeling strategy is proposed such that users can label a large group of similar regions each time. We also employ a tag refinement method such that several inappropriate tags can be automatically corrected. Experiments on a large dataset demonstrate the effectiveness of our approach
Shape perception of thin transparent objects with stereoscopic viewing
Authors: Chen Jianhui , Allison Robert S.
Published: August 2013

Many materials, including water surfaces, jewels, and glassware exhibit transparent refractions. The human visual system can somehow recover 3D shape from refracted images. While previous research has elucidated various visual cues that can facilitate visual perception of transparent objects, most of them focused on monocular material perception. The question of shape perception of transparent objects is much more complex and few studies have been undertaken, particular in terms of binocular vision.

In this article, we first design a system for stereoscopic surface orientation estimation with photo-realistic stimuli. It displays pre-rendered stereoscopic images and a real-time S3D (Stereoscopic 3D) shape probe simultaneously. Then we estimate people's perception of the shape of thin transparent objects using a gauge figure task. Our results suggest that people can consistently perceive the surface orientation of thin transparent objects, and stereoscopic viewing improves the precision of estimates. To explain the results, we present an edge-aware orientation map based on image gradients and structure tensors to illustrate the orientation information in images. We also decomposed the normal direction of the surface into azimuth angle and slant angle to explain why additional depth information can improve the accuracy of perceived normal direction.
Qualification of TRACE V5.0 Code against Fast Cooldown Transient in the PKL-III Integral Test Facility
Authors: Coscarelli Eugenio , Del Nevo Alessandro , D'Auria Francesco
Published: August 2013

The present paper deals with the analytical study of the PKL experiment G3.1 performed using the TRACE code (version 5.0 patch1). The test G3.1 simulates a fast cooldown transient, namely, a main steam line break. This leads to a strong asymmetry caused by an increase of the heat transfer from the primary to the secondary side that induces a fast cooldown transient on the primary side-affected loop. The asymmetric overcooling effect requires an assessment of the reactor pressure vessel integrity considering PTS (pressurized thermal shock) and an assessment of potential recriticality following entrainment of colder water into the core area. The aim of this work is the qualification of the heat transfer capabilities of the TRACE code from primary to secondary side in the intact and affected steam generators (SGs) during the rapid depressurization and the boiloff in the affected SG against experimental data.
Expression Profiling and Proteomic Analysis of JIN Chinese Herbal Formula in Lung Carcinoma H460 Xenografts
Authors: Zheng Luyu , Zhang Weiyi , Jiang Miao , Zhang Huarong , Xiong Fei , Yu Yang , Chen Meijuan , Zhou Jing , Dai Xiaoming , Tang Yuping , Jiang Ming , Wang Mingyan , Cheng Ge , Duan Jinao , Yu Wei , Lin Biaoyang , Fu Haian , Zhang Xu
Published: August 2013

Many traditional Chinese medicine (TCM) formulae have been used in cancer therapy. The JIN formula is an ancient herbal formula recorded in the classic TCM bookJin Kui Yao Lue(Golden Chamber). The JIN formula significantly delayed the growth of subcutaneous human H460 xenografted tumors in vivo compared with the growth of mock controls. Gene array analysis of signal transduction in cancer showed that the JIN formula acted on multiple targets such as the mitogen-activated protein kinase, hedgehog, and Wnt signaling pathways. The coformula treatment of JIN and diamminedichloroplatinum (DDP) affected the stress/heat shock pathway. Proteomic analysis showed 36 and 84 differentially expressed proteins between the mock and DDP groups and between the mock and JIN groups, respectively. GoMiner analysis revealed that the differentially expressed proteins between the JIN and mock groups were enriched during cellular metabolic processes, and so forth. The ones between the DDP and mock groups were enriched during protein-DNA complex assembly, and so forth. Most downregulated proteins in the JIN group were heat shock proteins (HSPs) such as HSP90AA1 and HSPA1B, which could be used as markers to monitor responses to the JIN formula therapy. The mechanism of action of the JIN formula on HSP proteins warrants further investigation.
Maximal and Area Integral Characterizations of Bergman Spaces in the Unit Ball ofℂn
Authors: Chen Zeqian , Ouyang Wei
Published: August 2013

We present maximal and area integral characterizations of Bergman spaces in the unit ball ofℂn. The characterizations are in terms of maximal functions and area integral functions on Bergman balls involving the radial derivative, the complex gradient, and the invariant gradient. As an application, we obtain new maximal and area integral characterizations of Besov spaces. Moreover, we give an atomic decomposition of real-variable type with respect to Carleson tubes for Bergman spaces.
Existence and Ulam Stability of Solutions for Discrete Fractional Boundary Value Problem
Authors: Chen Fulai , Zhou Yong
Published: August 2013

We discuss the existence of solutions for antiperiodic boundary value problem and the Ulam stability for nonlinear fractional difference equations. Two examples are also provided to illustrate our main results.
Model Based Control System Design Using SysML, Simulink, and Computer Algebra System
Authors: Sakairi Takashi , Palachi Eldad , Cohen Chaim , Hatsutori Yoichi , Shimizu Junya , Miyashita Hisashi
Published: August 2013

The Systems Modeling Language (SysML) is a standard, general-purpose, modeling language for model-based systems engineering (MBSE). SysML supports the specification, analysis, and design of a broad range of complex systems such as control systems. The authors demonstrate how they can integrate a SysML modeling tool (IBM Rational Rhapsody) with a proprietary simulation tool (MathWorks Simulink) and a Computer Algebra System (CAS) to validate system specification. The integration with Simulink enables users to perform systems engineering process in a SysML model, while designing continuous control algorithms and plant behavior in Simulink, and to validate the behavior by simulating the overall composition in Simulink. The integration with a CAS enables the evaluation of mathematical constraints defined in SysML parametric diagrams. The authors also show the overall approach using a Dual Clutch Transmission (DCT) and a Cruise Control System as examples.
The Usefulness of Confusion, Urea, Respiratory Rate, and Shock Index or Adjusted Shock Index Criteria in Predicting Combined Mortality and/or ICU Admission Compared to CURB-65 in Community-Acquired Pneumonia
Authors: Curtain James P. , Sankaran Prasanna , Kamath Ajay V. , Myint Phyo K.
Published: August 2013

Background and Objectives. The study aims to assess the usefulness of age-independent criteria CURSI and temperature adjusted CURSI (CURASI) compared to CURB-65 in predicting community-acquired pneumonia (CAP) mortality. The criteria, CRSI and CRASI, were adapted for use in primary care and compared to CRB-65.Methods. A retrospective analysis of a prospectively identified cohort of community-acquired pneumonia inpatients was conducted. Outcomes were (1) mortality and (2) mortality and/or ICU admission within six weeks.Results. 95 patients (median age = 61 years) were included. All three criteria had similar sensitivity in predicting mortality alone, with CURB-65 having slightly higher specificity. When predicting mortality and/or intensive care admission, CURSI/CURASI showed higher sensitivity and slightly lower specificity. CRSI and CRASI had higher sensitivity and lower specificity when compared with CRB-65 for predicting both primary and secondary outcomes. Results for both analyses hadPvalues >0.05.Conclusions. In a cohort of younger patients CURSI and adjusted CURSI perform at least as well as CURB-65, with a similar trend for CRSI and adjusted CRSI compared to CRB-65. Further studies are needed in different age groups and in primary and secondary care settings.
Hypoxic Pulmonary Vasoconstriction in Humans
Authors: Ariyaratnam Priyadharshanan , Loubani Mahmoud , Morice Alyn H.
Published: August 2013

Hypoxic pulmonary vasoconstriction is the elegant theory put forward more than six decades ago to explain regional variations in perfusion within the lung in certain animal species in response to localised restrictions in oxygenation. Although considerable progress has been made to describe the phenomenon at the macroscopic level and explain it at the microscopic level, we are far from a universal agreement about the process in humans. This review attempts to highlight some of the important evidence bases of hypoxic pulmonary vasoconstriction in humans and the significant gaps in our knowledge that would need bridging.