bluuebunny/crossref_metadata_2025 huggingface dataset:
Egg shape mimicry in parasitic cuckoos
Authors: Attard M. R. G. , Medina I. , Langmore N. E. , Sherratt E.
Published: September 2017

Parasitic cuckoos lay their eggs in nests of host species. Rejection of cuckoo eggs by hosts has led to the evolution of egg mimicry by cuckoos, whereby their eggs mimic the colour and pattern of their host eggs to avoid egg recognition and rejection. There is also evidence of mimicry in egg size in some cuckoo–host systems, but currently it is unknown whether cuckoos can also mimic the egg shape of their hosts. In this study, we test whether there is evidence of mimicry in egg form (shape and size) in three species of Australian cuckoos: the fan‐tailed cuckoo Cacomantis flabelliformis, which exploits dome nesting hosts, the brush cuckoo Cacomantis variolosus, which exploits both dome and cup nesting hosts, and the pallid cuckoo Cuculus pallidus, which exploits cup nesting hosts. We found evidence of size mimicry and, for the first time, evidence of egg shape mimicry in two Australian cuckoo species (pallid cuckoo and brush cuckoo). Moreover, cuckoo–host egg similarity was higher for hosts with open nests than for hosts with closed nests. This finding fits well with theory, as it has been suggested that hosts with closed nests have more difficulty recognizing parasitic eggs than open nests, have lower rejection rates and thus exert lower selection for mimicry in cuckoos. This is the first evidence of mimicry in egg shape in a cuckoo–host system, suggesting that mimicry at different levels (size, shape, colour pattern) is evolving in concert. We also confirm the existence of egg size mimicry in cuckoo–host systems.
Osteoporotic fractures may impair life as much as the complications of diabetes
Authors: Vokó Zoltán , Gáspár Katalin , Inotai András , Horváth Csaba , Bors Katalin , Speer Gábor , Kaló Zoltán
Published: September 2017

Rationale, aims, and objectives

To compare the effect of osteoporotic fractures and complications of diabetes mellitus on quality of life (QoL).

Method

A cross‐sectional study was performed in 840 patients with osteoporosis and in 943 patients with diabetes in Hungary to estimate the effect of osteoporotic fractures and microvascular and macrovascular complications of diabetes on QoL using the EQ‐5D questionnaire. Ordinary least‐squares regression was performed for the analysis to control for age and gender.

Results

The effects of certain of osteoporotic fractures and diabetes complications were similar in size measured by the EQ‐5D. Patients with hip fractures and compressions of the vertebrae suffered more than 0.2 drop in their QoL, which is comparable in size to the most severe complications of diabetes, such as vision loss and amputations.

Conclusions

The use of mortality and premature mortality as the traditional measures of disease burden in public health policy making means that diseases which strongly affect QoL but less survival might not get the necessary priority. This is especially the case in low‐income and middle‐income countries where studies on QoL are scarce. Our comparative analysis, which showed that osteoporotic fractures reduce QoL as much as major complications of diabetes, highlights the need for comprehensive disease burden assessment, including losses in functionality and QoL, to support decision making.
Distressing Symptoms, Disability, and Hospice Services at the End of Life: Prospective Cohort Study
Authors: Gill Thomas M. , Han Ling , Leo‐Summers Linda , Gahbauer Evelyne A. , Allore Heather G.
Published: September 2017

Objectives

To evaluate the relationship between the presence and number of restricting symptoms and number of disabilities and subsequent admission to hospice at the end of life.

Design

Prospective cohort study.

Setting

Greater New Haven, Connecticut, from March 1998 to December 2014.

Participants

Decedents from a cohort of 754 persons aged 70 and older (N = 562).

Measurements

Hospice admissions were identified primarily from Medicare claims, and 15 restricting symptoms and disability in 13 activities were assessed during monthly interviews.

Results

During their last year of life, 244 (43.4%) participants were admitted to hospice. The median duration of hospice was 12.5 days (interquartile range 4–43 days). Although the largest increases were observed in the last 2 months of life, the prevalence of restricting symptoms and mean number of restricting symptoms and disabilities in the preceding months were high and trending upward. During a specific month, the likelihood of hospice admission increased by 66% (adjusted hazard ratio (aHR) = 1.66, 95% confidence interval (CI) = 1.30–2.12) in the setting of any restricting symptoms, by 9% (aHR = 1.09, 95% CI = 1.05–1.12) for each additional restricting symptom, and by 10% (aHR = 1.10, 95% CI = 1.05–1.14) for each additional disability. Each additional month with any restricting symptoms increased the likelihood of hospice admission by 7% (aHR = 1.07, 95% CI = 1.01–1.13).

Conclusion

Hospice services appear to be suitably targeted to older persons with the greatest needs at the end of life, although the short duration of hospice suggests that additional strategies are needed to better address the high burden of distressing symptoms and disability at the end of life.
Racial Differences in the Association Between Apolipoprotein E Risk Alleles and Overall and Total Cardiovascular Mortality Over 18 Years
Authors: Rajan Kumar B. , Barnes Lisa L. , Wilson Robert S. , McAninch Elizabeth A. , Weuve Jennifer , Sighoko Dominique , Evans Denis A.
Published: September 2017

Objectives

To examine the difference in the association between apolipoprotein (APO)E allele and overall and cardiovascular mortality between African Americans (AAs) and European Americans (EAs).

Design

Longitudinal, cohort study of 18 years.

Setting

Biracial urban US population sample.

Participants

4,917, 68% AA and 32% EA.

Measurements

APOE genotype and mortality based on National Death Index.

Results

A higher proportion of AAs than of EAs had an APOE ε2 allele (ε2ε2/ε2ε3/ε2ε4; 22% vs 13%) and an APOE ε4 allele (ε3ε4/ε4ε4; 33% vs 24%). After adjusting for known risk factors, the risk of mortality was 19% less with the APOE ε2 allele (hazard ratio (HR) = 0.81, 95% confidence interval (CI) = 0.76–0.87), and the risk of cardiovascular mortality was 35% less (HR = 0.65, 95% CI = 0.58–0.76) than with the ε3ε3 allele. The risk of mortality was 10% greater with the APOE ε4 allele (HR = 1.10, 95% CI = 1.04–1.16), and the risk of cardiovascular mortality was 20% greater (HR = 1.20, 95% CI = 1.07–1.29) than with the ε3ε3 allele. No difference in the association between APOE allele and mortality was observed between AAs and EAs.

Conclusion

The APOE ε4 allele increased the risk of overall and cardiovascular mortality, whereas the APOE ε2 allele decreased the risk of overall and cardiovascular mortality. There was no racial difference in the association between these alleles and mortality.
The effects of optimism, religion, and hope on mood and anxiety disorders in women with the FMR1 premutation
Authors: Lowell E. P. , Tonnsen B. L. , Bailey D. B. , Roberts J. E.
Published: September 2017

Background

The FMR1 premutation, caused by a CGG trinucleotide repeat expansion on the FMR1 gene, has been identified as a genetic risk factor for mood and anxiety disorders. Building on recent studies identifying increased risk for mood and affective disorders in this population, we examined effects of potential protective factors (optimism, religion, hope) on depression and anxiety diagnoses in a prospective, longitudinal cohort.

Methods

Eighty‐three women with the FMR1 premutation participated in the Structured Clinical Interview for DSM‐IV‐TR Disorders at two‐time points, 3 years apart. Participants also completed measures of optimism, religion, personal faith, hope, and child and family characteristics. We used logistic regression to examine correlates of major depressive disorder (MDD) and anxiety disorders at the initial assessment, as well as predictors of the diagnostic course over time.

Results

Lower optimism and higher religious participation relevant to fragile X syndrome at the initial assessment were associated with a lifetime history of MDD. Lower optimism also predicted the occurrence and reoccurrence of an anxiety disorder 3 years later.

Conclusions

In women with the FMR1 premutation, elevated optimism may reduce the occurrence or severity of MDD and anxiety disorders. These findings underscore the importance of supporting mental health across the FMR1 spectrum of involvement.
Physical and mental health of young people with and without intellectual disabilities: cross‐sectional analysis of a whole country population
Authors: Young‐Southward G. , Rydzewska E. , Philo C. , Cooper S.‐A.
Published: September 2017

Background

Transition to adulthood may be a period of vulnerability for health for individuals with intellectual disabilities. No large‐scale studies have compared the health of individuals with and without intellectual disabilities undergoing transition. The aims of this study were (1) to compare health during transition for individuals with and without intellectual disabilities across a whole country population and (2) to establish whether transition is associated with health in the population with intellectual disabilities.

Methods

Data were drawn from Scotland's Census, 2011. Frequency data were calculated for young people with and without intellectual disabilities. Logistic regressions were used to determine the extent to which intellectual disabilities account for seven health outcomes (general health, mental health, physical disabilities, hearing impairment, visual impairment, long‐term illness and day‐to‐day activity limitations), adjusted for age and gender. Within the intellectual disabilities population, logistic regressions were then used to determine whether age group (13–18 or 19–24 years) is associated with the seven health outcomes, adjusted by gender.

Results

A total of 5556/815 889 young people aged 13–24 years had intellectual disabilities. Those with intellectual disabilities were 9.6–125.0 times more likely to have poor health on the seven outcomes. Within the population with intellectual disabilities, the 19‐ to 24‐year‐olds with intellectual disabilities were more likely to have mental health problems than the 13‐ to 18‐year‐olds, but did not have poorer health on the other outcomes. The difference between age groups for mental health problems was greater for young people who did not have intellectual disabilities, but their overall level of mental health problems was substantially lower than for the young people with intellectual disabilities.

Conclusions

This largest‐to‐date study quantifies the extent of the substantial health disparities experienced by young people with intellectual disabilities compared with people without intellectual disabilities. The young population with intellectual disabilities have substantial health problems; therefore, transition between child and adult services must be carefully planned in order to ensure that existing health conditions are managed and emerging problems minimised.
Growth ofPseudomonas aeruginosain zinc poor environments is promoted by a nicotianamine‐related metallophore
Authors: Mastropasqua Maria Chiara , D'Orazio Melania , Cerasi Mauro , Pacello Francesca , Gismondi Angelo , Canini Antonella , Canuti Lorena , Consalvo Ada , Ciavardelli Domenico , Chirullo Barbara , Pasquali Paolo , Battistoni Andrea
Published: September 2017

Previous studies have suggested thatP.aeruginosapossesses redundant zinc uptake systems. To identify uncharacterized zinc transporters, we analyzed the genome‐wide transcriptional responses ofP.aeruginosaPA14 to zinc restriction. This approach led to the identification of an operon (zrmABCD) regulated by the zinc uptake regulator Zur, that encodes for a metallophore‐mediated zinc import system. This operon includes the genes for an uncharacterized TonB‐dependent Outer Membrane Protein (ZrmA) and for a putative nicotianamine synthase (ZrmB). The simultaneous inactivation of the ZnuABC transporter and of one of these two genes markedly decreases the ability ofP.aeruginosato grow in zinc‐poor media and compromises intracellular zinc accumulation. Our data demonstrate that ZrmB is involved in the synthesis of a metallophore which is released outside the cell and mediates zinc uptake through the ZrmA receptor. We also show that alterations in zinc homeostasis severely affect the ability ofP.aeruginosato cause acute lung and systemic infections in C57BL/6 mice, likely due to the involvement of zinc in the expression of several virulence traits. These findings disclose a hitherto unappreciated role of zinc inP.aeruginosapathogenicity and reveal that this microorganism can obtain zinc through a strategy resembling siderophore‐mediated iron uptake.
Structural and thermodynamic characterization of metal binding in Vps29 from Entamoeba histolytica: implication in retromer function
Authors: Srivastava Vijay Kumar , Yadav Rupali , Watanabe Natsuki , Tomar Priya , Mukherjee Madhumita , Gourinath Samudrala , Nakada‐Tsukui Kumiko , Nozaki Tomoyoshi , Datta Sunando
Published: September 2017

Vps29 is the smallest subunit of retromer complex with metallo‐phosphatase fold. Although the role of metal in Vps29 is in quest, its metal binding mutants has been reported to affect the localization of the retromer complex in human cells. In this study, we report the structural and thermodynamic consequences of these mutations in Vps29 from the protozoan parasite, Entamoeba histolytica (EhVps29). EhVps29 is a zinc binding protein as revealed by X‐ray crystallography and isothermal titration calorimetry. The metal binding pocket of EhVps29 exhibits marked differences in its 3‐dimensional architecture and metal coordination in comparison to its human homologs and other metallo‐phosphatases. Alanine substitutions of the metal‐coordinating residues showed significant alteration in the binding affinity of EhVps29 for zinc. We also determined the crystal structures of metal binding defective mutants (D62A and D62A/H86A) of EhVps29. Based on our results, we propose that the metal atoms or the bound water molecules in the metal binding site are important for maintaining the structural integrity of the protein. Further cellular studies in the amoebic trophozoites showed that the overexpression of wild type EhVps29 leads to reduction in intracellular cysteine protease activity suggesting its crucial role in secretion of the proteases.
The genetics of drought tolerance in conifers
Authors: Moran Emily , Lauder Jeffrey , Musser Cameron , Stathos Angela , Shu Mengjun
Published: September 2017

As temperatures warm and precipitation patterns shift as a result of climate change, interest in the identification of tree genotypes that will thrive under more arid conditions has grown. In this review, we discuss the multiple definitions of ‘drought tolerance’ and the biological processes involved in drought responses. We describe the three major approaches taken in the study of genetic variation in drought responses, the advantages and shortcomings of each, and what each of these approaches has revealed about the genetic basis of adaptation to drought in conifers. Finally, we discuss how a greater knowledge of the genetics of drought tolerance may aid forest management, and provide recommendations for how future studies may overcome the limitations of past approaches. In particular, we urge a more direct focus on survival, growth and the traits that directly predict them (rather than on proxies, such as water use efficiency), combining research approaches with complementary strengths and weaknesses, and the inclusion of a wider range of taxa and life stages.

Contents

Summary
1034

I.
Introduction
1034

II.
Drought tolerance
1035

III.
Investigation of the genetic basis of drought tolerance: three main approaches
1037

IV.
Conifer drought tolerance genetics: what we know
1038

V.
Implications for the management of forests in a changing world
1042

VI.
Future directions
1043

VII.
Conclusion
1045

References
1045
TGACG‐BINDING FACTOR 1 (TGA1) and TGA4 regulate salicylic acid and pipecolic acid biosynthesis by modulating the expression of SYSTEMIC ACQUIRED RESISTANCE DEFICIENT 1 (SARD1) and CALMODULIN‐BINDING PROTEIN 60g (CBP60g)
Authors: Sun Tongjun , Busta Lucas , Zhang Qian , Ding Pingtao , Jetter Reinhard , Zhang Yuelin
Published: September 2017

Salicylic acid (SA) and pipecolic acid (Pip) play important roles in plant immunity. Here we analyzed the roles of transcription factors TGACG‐BINDING FACTOR 1 (TGA1) and TGA4 in regulating SA and Pip biosynthesis in Arabidopsis thaliana.

We quantified the expression levels of SYSTEMIC ACQUIRED RESISTANCE DEFICIENT 1 (SARD1) and CALMODULIN‐BINDING PROTEIN 60g (CBP60g), which encode two master transcription factors of plant immunity, and the accumulation of SA and Pip in tga1‐1 tga4‐1 mutant plants. We tested whether SARD1 and CBP60g are direct targets of TGA1 by chromatin immunoprecipitation−polymerase chain reaction (ChIP‐PCR).

In addition to promoting pathogen‐induced SA biosynthesis, we found that SARD1 and CBP60g also positively regulated Pip biosynthesis by targeting genes encoding key biosynthesis enzymes of Pip. TGA1/TGA4 were required for full induction of SARD1 and CBP60g in plant defense. ChIP‐PCR analysis showed that SARD1 was a direct target of TGA1. In tga1‐1 tga4‐1 mutant plants, the expression levels of SARD1 and CBP60g along with SA and Pip accumulation following pathogen infection were dramatically reduced compared with those in wild‐type plants. Consistent with reduced expression of SARD1 and CBP60g, pathogen‐associated molecular pattern (PAMP)‐induced pathogen resistance and systemic acquired resistance were compromised in tga1‐1 tga4‐1.

Our study showed that TGA1 and TGA4 regulate Pip and SA biosynthesis by modulating the expression of SARD1 and CBP60g.
Off the pedal: Fluoroless transseptal puncture in pediatric supraventricular tachycardia ablation
Authors: Clark Bradley C. , Sumihara Kohei , Berul Charles I. , Moak Jeffrey P.
Published: September 2017

Background

Fluoroless transseptal (TS) puncture may represent the final step toward elimination of fluoroscopy in pediatric supraventricular tachycardia ablation in normal hearts. We aimed to demonstrate the safety and feasibility of fluoroless TS puncture in pediatric patients and compare procedural timing with the fluoroscopic approach.

Methods

We performed a retrospective cohort analysis of all TS procedures performed without fluoroscopy at our institution; fluoroless TS procedures were performed under intracardiac echocardiography (ICE) guidance after the creation of a 3D electroanatomic map and identification of fossa ovalis (FO) on 3D map. TS procedure times reported are the time from sheath insertion (8.5F short sheath for ICE catheter and SL‐1 for TS needle) to the time of confirmed left atrial access. Prior TS procedures performed by the same operator utilizing a combination of ICE and fluoroscopy and by a second operator utilizing fluoroscopic guidance alone were used for comparison.

Results

Fluoroless TS puncture was performed in nine patients (mean age 13.8 years); the site of TS puncture was within 2 mm of the FO identified on the EA map. The mean TS procedure time was 22.2 minutes (range 10–45). There was no significant difference in TS procedure times between the three groups. There were no complications related to any TS procedure.

Conclusion

Fluoroless TS procedures utilizing ICE can safely be performed in pediatric patients without adding substantial procedural times compared with those utilizing fluoroscopic guidance.
Initiating Supplier New Product Development Projects: A Behavioral Investigation
Authors: Wuttke David A. , Donohue Karen , Siemsen Enno
Published: September 2017

While suppliers are often an excellent source of product innovation for buyers, their propensity to undertake or continue a product development project can be elusive. This study examines how characteristics of the innovation project, including the type of project revenue, type of cost uncertainty, and the contract frame, influence the decision to accept, and subsequently continue, an innovation project. Through a series of controlled behavioral experiments, we find that acceptance rates increase when projects are characterized by a low real options value or an entirely new (vs. replacement) revenue stream. While these factors have less influence on the supplier's decision to continue the project, once accepted, continuation rates do increase if acceptance and continuation decisions are made by the same person. We also find that using a reward (vs. penalty) frame for sustaining supplier engagements significantly increases acceptance rates.
Prevalence of Autism Spectrum Disorders with and without Intellectual Disability by Gestational Age at Birth in the Stockholm Youth Cohort: a Register Linkage Study
Authors: Xie Sherlly , Heuvelman Hein , Magnusson Cecilia , Rai Dheeraj , Lyall Kristen , Newschaffer Craig J. , Dalman Christina , Lee Brian K. , Abel Kathryn
Published: September 2017

Background

Preterm birth has been linked to increased risk of autism spectrum disorders (ASD), but how this risk changes with gestational age at birth has not been well characterised, especially with regard to co‐occurring intellectual disability (ID).

Methods

Register‐based cohort study of singleton births in 1984–2007 in Stockholm County, Sweden (N total: 480 728; n ASD: 10 025). We assessed overall and sex‐specific, gestational week‐specific prevalence estimates and risk ratios of ASD with and without ID.

Results

Preterm and postterm births were associated with elevated risk of ASD, and the relationship between gestational age at birth and ASD with and without ID differed in males and females. Risk of ASD without ID was higher in preterm births among both sexes and decreased continuously with increasing length of gestation. Risk of ASD with ID was higher in both preterm and postterm births among both sexes, with postterm birth in females being more highly associated with ASD with ID than that in males.

Conclusions

The relationship between gestational age at birth and ASD differs by the presence/absence of co‐occurring ID and fetal sex. Both preterm and postterm birth are associated with increased risk of ASD. Risk of ASD is not constant within conventionally defined gestational age at birth periods. Further research on mechanism underlying these associations is needed.
Political reservation for women and delivery of public works program
Authors: Bose Nayana , Das Shreyasee
Published: September 2017

We examine the impact of political reservations for women to analyze the effectiveness of female leaders in executing public works under NREGA, India's largest public works program. The 73rd Amendment to the Indian Constitution mandated that one third of Panchayat seats be randomly assigned to women. Using detailed data on Panchayat elections, employment, and public works expenditure for nine districts in Uttar Pradesh, we find female Panchayat leaders significantly increase the demand for work under NREGA. We also find that women leaders take up projects that directly benefit women, such as water control and harvesting. Finally, we find no difference between male and female leaders in generating employment or efficiently implementing public works under NREGA.
Depoliticisation in Livestock Farming Governance: Turning Citizen Concerns into Consumer Responsibilities
Authors: van Wessel Margit
Published: September 2017

The Dutch livestock farming sector faces complex challenges concerning its sustainability and social license to operate. Engaging with what is widely understood as a legitimacy crisis, the Dutch government organised a two‐day multi‐stakeholder meetings to explore future directions. Participants engaged with the public as a key but absent stakeholder, in ways that contributed to the outcome of the meetings in important ways. The paper charts and analyses how and with what consequences this happened. Findings are that participants discursively constructed citizens in terms of consumer roles, with deliberations turning citizen concerns about livestock farming into questions of consumer responsibility, side‐lining citizens’ political voices and discursively displacing the possibility of politics around livestock farming. This instance of network governance presents a case of depoliticisation of an issue of concern to citizens, closely related to market players being put in the driver's seat of change, with the government in a supporting role. The article argues that this raises significant questions on the nature and role of construction of publics in network governance.
Wisdom in a complex world: A situated account of wise reasoning and its development
Authors: Santos Henri C. , Huynh Alex C. , Grossmann Igor
Published: September 2017

Social issues (e.g., partisan politics, economic decisions, and interpersonal conflicts) often involve trade‐offs, necessitating the consideration of multiple interests. Such issues do not have simple answers and benefit from wise reasoning—a set of metacognitive strategies that guide people toward managing complexity and balancing different interests. We review recent advances in research on wise reasoning, including evidence pertinent to the question of wisdom's trait‐like and state‐specific features, how it varies across situations, and how one can develop it. Overall, empirical studies suggest that researchers can understand wisdom better by paying attention to its situated nature across time and contexts.
Rotordynamics of a Highly Flexible Hub for Inside-Out Ceramic Turbine Application: Finite Element Modeling and Experimental Validation
Authors: Landry Céderick , Dubois Patrick K. , Plante Jean-Sébastien , Charron François , Picard Mathieu
Published: September 2017

The inside-out ceramic turbine (ICT) is a promising concept to increase turbine inlet temperatures in microturbines by integrating individual monolithic ceramic. This architecture uses a carbon–polymer composite rim to support the blades mainly in compression. High tangential velocities lead to elevated radial displacement of the rim, and therefore, the rotor hub needs to have sufficient compliance to follow this radial displacement. However, the rotordynamics of a flexible hub is not widely understood. This paper presents the rotordynamic analysis of a highly flexible hub for an ICT architecture. Finite element modeling (FEM) is used to design a simplified turbine prototype that maximizes the hub flexibility to explore the limits of the concept. The rotordynamics behavior of the highly flexible hub is measured by spinning a 171-mm diameter prototype up to 49 krpm. This paper highlights three principal challenges of this particular rotordynamics. First, critical speeds mode shape becomes highly coupled with bearings displacement, shaft bending, and hub deformation. At high-speed, the hub deforms out of phase with the shaft, which can cause high stresses in the hub. Second, the angular position between unbalance masses of the flexible hub and the composite rim changes the unbalance response significantly. Finally, vibration causes high stresses in the hub, due to the relative displacement between the composite rim and the shaft, which could lead to failure of the hub. Nevertheless, the rotordynamics of an ICT configuration is manageable as long as the vibration-induced stress in the hub is kept under its limit.
Transmission loss of plates with embedded acoustic black holes
Authors: Feurtado Philip A. , Conlon Stephen C.
Published: September 2017

In recent years acoustic black holes (ABHs) have been developed and demonstrated as an effective method for developing lightweight, high loss structures for noise and vibration control. ABHs employ a local thickness change to tailor the speed and amplitude of flexural bending waves and create concentrated regions of high strain energy which can be effectively dissipated through conventional damping treatments. These regions act as energy sinks which allow for effective broadband vibration absorption with minimal use of applied damping material. This, combined with the reduced mass from the thickness tailoring, results in a treated structure with higher loss and less mass than the original. In this work, the transmission loss (TL) of plates with embedded ABHs was investigated using experimental and numerical methods in order to assess the usefulness of ABH systems for TL applications. The results demonstrated that damped ABH plates offer improved performance compared to a uniform plate despite having less mass. The result will be useful for applying ABHs and ABH systems to practical noise and vibration control problems.
Power law transfer matrix and the acoustic impedance of Gabriel's Horn
Authors: Brown W. Robert
Published: September 2017

One dimensional acoustic waveguides such as tubes and musical instruments can be mathematically characterized by a 2 × 2 transfer matrix which relates the pressure and flow at the inlet to the outlet of the waveguide. Matrix elements are a function of the geometry of the waveguide, frequency, and the speed of sound in the fluid medium. Transfer matrices are a mathematically convenient representation of waveguides because multiple waveguides may be easily combined, and certain characteristics such as sound transmission loss and impedance can be derived from them. Impedance maxima are frequencies where a small excitation of the volume flow results in high sound pressure. Brass instruments are usually played near these resonant frequencies. A derivation of the terms of a waveguide transfer matrix is presented and analytical solutions are shown for an assortment of geometries including waveguides with cross sectional areas varying according to a power law. This information is then used to calculate the normalized impedance of a well defined but non-physical instrument, Gabriel's Horn, which has infinite length, infinite surface area, yet finite volume. The impedance of Gabriel's Horn is compared to that of cylinders of equivalent length and input area.
A natural ligand for the orphan receptor GPR15 modulates lymphocyte recruitment to epithelia
Authors: Suply Thomas , Hannedouche Sébastien , Carte Nathalie , Li Jianping , Grosshans Bianka , Schaefer Michael , Raad Layla , Beck Valérie , Vidal Solange , Hiou-Feige Agnès , Beluch Noémie , Barbieri Samuel , Wirsching Johann , Lageyre Nadine , Hillger Frank , Debon Corinne , Dawson Janet , Smith Philip , Lannoy Vincent , Detheux Michel , Bitsch Francis , Falchetto Rocco , Bouwmeester Tewis , Porter Jeffrey , Baumgarten Birgit , Mansfield Keith , Carballido José M. , Seuwen Klaus , Bassilana Frédéric
Published: September 2017

The identification of a natural ligand of the orphan chemoattractant receptor GPR15 provides mechanistic insight into the migration of lymphocytes in the skin.
Papers of note in
Science
357
(6355)
Authors: VanHook Annalisa M.
Published: September 2017

This week’s articles describe an alternative mechanism of secretion that is deployed by intestinal cells in the presence of pathogens; how the immune system protects the lungs from inhaled fungal spores; and metabolic reprogramming of tissue-resident antigen-presenting cells in the lung.
Leaky nuclei lead to senescence
Authors: Wong Wei
Published: September 2017

A pathway that senses microbial DNA also promotes senescence in cells with cytosolic chromatin fragments.
Paper of note in
Science Translational Medicine
9
(406)
Authors: Ferrarelli Leslie K.
Published: September 2017

This week’s article describes how targeted antimicrobials may reduce the virulence of
Clostridium difficile
infection.
Identification of Heparin Modifications and Polysaccharide Inhibitors of Plasmodium falciparum Merozoite Invasion That Have Potential for Novel Drug Development
Authors: Boyle Michelle J. , Skidmore Mark , Dickerman Benjamin , Cooper Lynsay , Devlin Anthony , Yates Edwin , Horrocks Paul , Freeman Craig , Chai Wengang , Beeson James G.
Published: September 2017

Despite recent successful control efforts, malaria remains a leading global health burden. Alarmingly, resistance to current antimalarials is increasing and the development of new drug families is needed to maintain malaria control. Current antimalarials target the intraerythrocytic developmental stage of the
Plasmodium falciparum
life cycle. However, the invasive extracellular parasite form, the merozoite, is also an attractive target for drug development. We have previously demonstrated that heparin-like molecules, including those with low molecular weights and low anticoagulant activities, are potent and specific inhibitors of merozoite invasion and blood-stage replication. Here we tested a large panel of heparin-like molecules and sulfated polysaccharides together with various modified chemical forms for their inhibitory activity against
P. falciparum
merozoite invasion. We identified chemical modifications that improve inhibitory activity and identified several additional sulfated polysaccharides with strong inhibitory activity. These studies have important implications for the further development of heparin-like molecules as antimalarial drugs and for understanding merozoite invasion.
Genomic and Molecular Characterization of Clinical Isolates of Enterobacteriaceae Harboring
mcr-1
in Colombia, 2002 to 2016
Authors: Saavedra Sandra Yamile , Diaz Lorena , Wiesner Magdalena , Correa Adriana , Arévalo Stefany Alejandra , Reyes Jinnethe , Hidalgo Andrea Melissa , de la Cadena Elsa , Perenguez Marcela , Montaño Lucy Angeline , Ardila Javier , Ríos Rafael , Ovalle María Victoria , Díaz Paula , Porras Paola , Villegas Maria V. , Arias Cesar A. , Beltrán Mauricio , Duarte Carolina
Published: September 2017

Polymyxins are last-resort antimicrobial agents used to treat infections caused by carbapenem-resistant
Enterobacteriaceae
. Due to the worldwide dissemination of polymyxin resistance in animal and human isolates, we aimed to characterize polymyxin resistance associated with the presence of
mcr-1
in
Enterobacteriaceae
and nonfermenter Gram-negative bacilli, using isolates collected retrospectively in Colombia from 2002 to 2016. A total of 5,887 Gram-negative clinical isolates were studied, and 513 were found to be resistant to the polymyxins. Susceptibility to colistin was confirmed by broth microdilution for all
mcr-1
-positive isolates, and these were further subjected to whole-genome sequencing (WGS). The localization of
mcr-1
was confirmed by S1 pulsed-field gel electrophoresis (S1-PFGE) and CeuI-PFGE hybridization. Transferability was evaluated by mating assays. A total of 12 colistin-resistant isolates recovered after 2013 harbored
mcr-1
, including 8
Escherichia coli
, 3
Salmonella enterica
serovar Typhimurium, and 1
Klebsiella pneumoniae
isolate
. E. coli
isolates were unrelated by PFGE and belonged to 7 different sequence types (STs) and phylogroups.
S
. Typhimurium and
K. pneumoniae
isolates belonged to ST34 and ST307, respectively. The
mcr-1
gene was plasmid borne in all isolates but two
E. coli
isolates which harbored it on the chromosome. Conjugation of
mcr-1
was successful in 8 of 10 isolates (8.2 × 10
−5
to 2.07 × 10
−1
cell per recipient). Plasmid sequences showed that the
mcr-1
plasmids belonged to four different Inc groups (a new IncP-1 variant and the IncFII, IncHI1, and IncH families). Our results indicate that
mcr-1
is circulating in clinical isolates of colistin-resistant
Enterobacteriaceae
in Colombia and is mainly harbored in transferable plasmids.
Evolution of Antibiotic Resistance without Antibiotic Exposure
Authors: Knöppel Anna , Näsvall Joakim , Andersson Dan I.
Published: September 2017

Antibiotic use is the main driver in the emergence of antibiotic resistance. Another unexplored possibility is that resistance evolves coincidentally in response to other selective pressures. We show that selection in the absence of antibiotics can coselect for decreased susceptibility to several antibiotics. Thus, genetic adaptation of bacteria to natural environments may drive resistance evolution by generating a pool of resistance mutations that selection could act on to enrich resistant mutants when antibiotic exposure occurs.
The Gene
tia
, Harbored by the Subtilase-Encoding Pathogenicity Island, Is Involved in the Ability of Locus of Enterocyte Effacement-Negative Shiga Toxin-Producing Escherichia coli Strains To Invade Monolayers of Epithelial Cells
Authors: Bondì Roslen , Chiani Paola , Michelacci Valeria , Minelli Fabio , Caprioli Alfredo , Morabito Stefano
Published: September 2017

Locus of enterocyte effacement (LEE)-negative Shiga toxin (Stx)-producing
Escherichia coli
(STEC) strains are human pathogens that lack the LEE locus, a pathogenicity island (PAI) involved in the intimate adhesion of LEE-positive strains to the host gut epithelium. The mechanism used by LEE-negative STEC strains to colonize the host intestinal mucosa is still not clear. The cell invasion determinant
tia
, previously described in enterotoxigenic
E. coli
strains, has been identified in LEE-negative STEC strains that possess the subtilase-encoding pathogenicity island (SE-PAI). We evaluated the role of the gene
tia
, present in these LEE-negative STEC strains, in the invasion of monolayers of cultured cells. We observed that these strains were able to invade Caco-2 and HEp-2 cell monolayers and compared their invasion ability with that of a mutant strain in which the gene
tia
had been inactivated. Mutation of the gene
tia
resulted in a strong reduction of the invasive phenotype, and complementation of the
tia
mutation with a functional copy of the gene restored the invasion activity. Moreover, we show that the gene
tia
is overexpressed in bacteria actively invading cell monolayers, demonstrating that
tia
is involved in the ability to invade cultured monolayers of epithelial cells shown by SE-PAI-positive
E. coli
, including STEC, strains. However, the expression of the
tia
gene in the
E. coli
K-12 strain JM109 was not sufficient, in its own right, to confer to this strain the ability to invade cell monolayers, suggesting that at least another factor must be involved in the invasion ability displayed by the SE-PAI-positive strains.
Characteristics of early filtering blebs that predict successful trabeculectomy identified via three-dimensional anterior segment optical coherence tomography
Authors: Narita Akiko , Morizane Yuki , Miyake Tomoe , Seguchi Jiro , Baba Tetsuya , Shiraga Fumio
Published: September 2017

Background/aims

To identify the cross-sectional characteristics of filtering blebs at 2 weeks post-trabeculectomy associated with intraocular pressure (IOP) control at 1 year post-trabeculectomy.

Methods

Ninety-nine eyes of 94 patients who had undergone primary trabeculectomy were included in this retrospective consecutive case series study. Surgical success was defined as an IOP ≤15 mm Hg and a >20% reduction in IOP without glaucoma medication or additional glaucoma surgeries at 1 year post-trabeculectomy. Subjects were classified into two groups according to whether surgery was successful or unsuccessful. Blebs were examined using swept-source three-dimensional anterior segment optical coherence tomography and evaluated for quantitative parameters, including maximum height, maximum wall thickness and ratio of hyporeflective space of the wall, as well as qualitative parameters, including multiple parallel hyporeflective layers within the wall (striping phenomenon), decreased visibility of the sclera underlying the bleb (shading phenomenon) and cyst-like structures of the wall.

Results

Seventy-seven eyes (77.8%) were assigned to the successful group and 22 (22.2%) to the unsuccessful group. Univariate analysis showed significant differences between the groups regarding maximum bleb height (p=0.044), maximum bleb wall thickness (p=0.017) and the striping phenomenon of the bleb wall (p=0.007). Multivariate logistic regression analysis confirmed that the striping phenomenon at 2 weeks post-trabeculectomy was significantly associated with success at 1 year post-trabeculectomy (OR 3.405; 95% CI 1.059 to 10.947; p=0.040).

Conclusion

Taller blebs with thicker walls that showed the striping phenomenon at 2 weeks post-trabeculectomy appeared to predict good IOP control at 1 year post-trabeculectomy.
Weight regain after Roux-en-Y gastric bypass has a large negative impact on the Bariatric Quality of Life Index
Authors: Jirapinyo Pichamol , Abu Dayyeh Barham K , Thompson Christopher C
Published: September 2017

Background

Despite initial successful weight loss, some patients may experience weight regain following Roux-en-Y gastric bypass (RYGB).

Objective

To assess the impact of weight regain on bariatric patients’ quality of life (QoL).

Methods

This was a prospective cross-sectional study. Fifty-six consecutive RYGB patients were recruited and divided into weight-regain and weight-stable cohorts. QoL was assessed using the Bariatric Quality of Life (BQL) questionnaire. The BQL Index scores of the weight-regain and weight-stable groups were compared using Student’st-test. Additionally, the BQL Index score of the weight-regain group was compared with that of historical prebariatric patients. Predictors of BQL were assessed using univariate and multivariate linear regression analyses.

Results

Of 56 RYGB patients, 41 (73%) had weight regain. On average, patients had body mass index (BMI) of 37 ±7.5 kg/m2and gained 34 ±26% of maximal weight initially lost. Weight-regain patients had lower BQL Index scores than weight-stable patients (44.8±6 vs 53±7, p<0.001). Patients with weight regain had similar BQL Index scores as the prebariatric patients despite lower BMI (BMI of 39.7±6.8 vs 47.2±7.6, p<0.05; BQL Index of 44.8±6 vs 41.6±10.4, p=0.144, respectively). Years from RYGB, BMI and amount of weight regain were associated with BQL Index on a univariate analysis (β=−0.55,−0.52, −0.7; p<0.0001). Only weight regain was a significant predictor of BQL on a multivariate analysis (β =−0.56; p=0.001).

Conclusion

Weight regain had a negative impact on bariatric patients’ QoL. Patients who regained at least 15% of maximal weight lost appeared to have as low QoL as those who had not undergone bariatric surgery despite a lower BMI.
Changes in dynamic lung mechanics after lung volume reduction coil treatment of severe emphysema
Authors: Makris Demosthenes , Leroy Sylvie , Pradelli Johana , Benzaquen Jonathan , Guenard Hervé , Perotin Jeanne-Marie , Zakynthinos Spyros , Zakynthinos Epaminondas , Deslee Gaëtan , Marquette Charles Hugo
Published: September 2017

We assessed the relationships between changes in lung compliance, lung volumes and dynamic hyperinflation in patients with emphysema who underwent bronchoscopic treatment with nitinol coils (coil treatment) (n=11) or received usual care (UC) (n=11). Compared with UC, coil treatment resulted in decreased dynamic lung compliance (CLdyn) (p=0.03) and increased endurance time (p=0.010). The change in CLdyn was associated with significant improvement in FEV1 and FVC, with reduction in residual volume and intrinsic positive end-expiratory pressure, and with increased inspiratory capacity at rest/and at exercise. The increase in end-expiratory lung volume (EELV) during exercise (EELVdyn-ch=EELVisotime EELVrest) demonstrated significant attenuation after coil treatment (p=0.02).
Passive Synthesis of a Class of Fractional Immittance Function Based on Multivariable Theory
Authors: Liang Guishu , Jing Yongming , Liu Chang , Ma Long
Published: September 2017

Passive synthesis of fractional driving-point immittance function is one of the most important research topics in fractional circuits. The synthesis method for a class of fractional driving-point immittance function is proposed in this paper. Firstly, the immittance function of passive fractional circuit is transformed to multivariable positive-real function by proper variable substitution. Secondly, to synthesize the function, except one variable, other high-order variables are transformed to the combination of products of different one-order variables by introducing new variables. Thirdly, synthesize the new function by traditional method. At last, substitute elements inversely twice and the final circuit for fractional driving-point immittance function can be achieved. The method is verified by giving synthesis demonstration.
Knot types of twisted torus knots
Authors: Lee Sangyop
Published: September 2017

Dean introduced twisted torus knots, which are obtained from a torus knot and a torus link by splicing them together along a number of adjacent strands of each of them. We study the knot types of these knots.
A dark energy model alternative to generalized Chaplygin gas
Authors: Hova Hoavo , Yang Huanxiong
Published: September 2017

By proposing a new cosmic fluid model of [Formula: see text] as an alternative to the generalized Chaplygin gas, we reexamine the role of Chaplygin gaslike fluid models in understanding dark energy and dark matter. Instead of as a unified dark matter, the fluid is suggested to be a mixture of unclustered dark energy and pressureless dark matter. Within such a scenario, the sub-horizon fluctuations of matter are stable and scale invariant, similar to those in standard [Formula: see text] model.
Broadband metamaterial perfect absorber obtained by coupling effect
Authors: Dang Hong Luu , Nguyen Van Cuong , Le Dinh Hai , Nguyen Hoang Tung , Tran Manh Cuong , Le Dac Tuyen , Vu Dinh Lam
Published: September 2017

We propose a new broadband metamaterial perfect absorber (MPA) based on structure of metallic dishes in the THz region. It demonstrated that the coupling interaction between the central dish and adjacent dishes leads to absorption characteristics. By optimizing the geometrical structure, the bandwidth is gained up to 1.0[Formula: see text]THz with absorption better than 90%. The mechanism of the absorption results was explained by induced current, magnetic and electric distributions. Furthermore, LC equivalent circuit was used to elucidate resonant frequencies. The obtained results can provide a general guideline for fabricating broadband MPA.
Structure of states for which each localized dynamics reduces to a localized subdynamics
Authors: Sargolzahi Iman , Mirafzali Sayyed Yahya
Published: September 2017

We consider a bipartite quantum system [Formula: see text] (including parties [Formula: see text] and [Formula: see text]), interacting with an environment [Formula: see text] through a localized quantum dynamics [Formula: see text]. We call a quantum dynamics [Formula: see text] localized if, e.g. the party [Formula: see text] is isolated from the environment and only [Formula: see text] interacts with the environment: [Formula: see text], where [Formula: see text] is the identity map on the part [Formula: see text] and [Formula: see text] is a completely positive (CP) map on the both [Formula: see text] and [Formula: see text]. We will show that the reduced dynamics of the system is also localized as [Formula: see text], where [Formula: see text] is a CP map on [Formula: see text], if and only if the initial state of the system-environment is a Markov state. We then generalize this result to the two following cases: when both [Formula: see text] and [Formula: see text] interact with a same environment, and when each party interacts with its local environment.