bluuebunny/crossref_metadata_2025 huggingface dataset:
Supplier Behavior in Capacity Investment Competition: An Experimental Study
Authors: Hu Shanshan , Wan Zhixi , Ye Qing , Chi Wei
Published: September 2016

Many manufacturers ensure supply capacity by using more than one supplier and sharing their capacity investment costs via supplier development programs. Their suppliers face competitive pressure from peers despite the reduced capacity investment cost. Although standard game theory makes clear prediction that cost sharing increases the suppliers' capacity choice and supply chain profit, the complex decision environment of capacity competition makes it interesting to test whether the theory predictions are robust and, if not, whether systematic deviations occur. We present a laboratory experiment study. The experiment data show that supplier subjects invested in higher capacities than what our theoretical analysis predicted, resulting in profit loss for the supply chain. Our econometric analysis indicates that the subjects are bounded rational and their concern for relative standing may be the potential driver of capacity over‐investment. Based on the experimental findings, we study a modified cost‐sharing mechanism that adapts to the behavioral biases. Its performance is validated in a second experiment.
Ecological restoration by soil transfer: impacts on restored soil profiles and topsoil functions
Authors: Bulot Adeline , Potard Kevin , Bureau Fabrice , Bérard Annette , Dutoit Thierry
Published: September 2016

A last resort means to restoring a severely degraded ecosystem can involve soil transfer, especially when destruction of an undegraded system has been previously independently planned. We measured the impact of different soil transfer treatments that varied in vertical and orderly reconstitution of the main soil horizons on the microbial activity and organic matter composition during restoration of a Haplic Cambisol in a steppe ecosystem. There were differences between the topsoil of the reference ecosystem and the soil transfer treatments in terms of physicochemical parameters and microbial activity, but this was not the case when topsoil was not replaced at the soil surface. Three years following restoration, the transferred topsoil treatment, where the three main soil layers were transferred, contained lower particulate organic matter content than the steppe reference soil, despite similarity in potential carbon mineralization. Soil profile descriptions revealed strong differences in overall organization between the transferred soil and the undisturbed steppe soil, particularly with respect to lower biological activity and a lack of connectivity between pedological horizons via the plant root systems and the earthworm activity in the transferred soil. This suggests that soil transfer conducted to retain soil horizons provides good results when the topsoil is transferred, but it may result in altered biological activity, profile morphology, and organic matter content compared with the reference system.
Knowledge about Chemicals in e‐Cigarette Secondhand Vapor and Perceived Harms of Exposure among a National Sample of U.S. Adults
Authors: Tan Andy S. L. , Mello Susan , Sanders‐Jackson Ashley , Bigman Cabral A.
Published: September 2016

Potentially harmful chemicals are detectable in e‐cigarette secondhand vapor (hereafter SHV), contrary to advertising and marketing claims that it contains “only water vapor.” We assessed public knowledge about the presence of chemicals in SHV and associations between knowledge and perceived harms of exposure to SHV. We conducted an online survey of a nationally representative sample of 1,449 U.S. adults (GfK's KnowledgePanel) from October to December 2013. Respondents were asked whether e‐cigarette vapor contains only water vapor, contains tar, or contains formaldehyde (true/ false/ do not know). Responses to these three items were recoded (1 = incorrect, 2 = do not know, and 3 = correct) and averaged into a knowledge scale. They were also asked if they perceived breathing SHV to be harmful to one's health (two‐item scale) and comparative harm of breathing SHV versus breathing secondhand smoke (SHS). Multiple regression analyses were weighted to the U.S. adult population and adjusted for potential confounders. Most respondents (58–75%) reported not knowing whether SHV contained only water vapor, if SHV contained tar, and if it contained formaldehyde. African‐American respondents (vs. white) and current smokers (vs. nonsmokers) had lower levels of knowledge about chemicals in SHV. Adjusting for covariates, correct knowledge about chemicals in SHV was associated with higher perceived harms about SHV for one's health and perceived comparative harm of SHV versus SHS. These findings suggest a need to provide accurate information about the presence of chemicals in SHV (e.g., using product ingredient labels or public education).
Context, Orders of Worth, and the Justification of Meat Consumption Practices
Authors: Thorslund Cecilie A. H. , Lassen Jesper
Published: September 2016

Although animal welfare is felt to be important by consumers, behavioural patterns do not fully reflect this. Rather than relating this attitude‐behaviour gap to hypocrisy, this article, building on pragmatic sociological theory and an empirical study, focuses on context‐dependent moral evaluations. An analysis of focus‐group interviews conducted in three countries shows that meat‐related consumption practices involve several competing sets of moral conventions, and the results demonstrate that public concerns about animal welfare vary depending on whether they relate to an everyday or production context. In the former, animal welfare does not play a big role, and given this it can be argued that people are not hypocritical, since the practices and perceptions are actually united within the given context. It is concluded that the lack of civic justifications in the context of everyday life calls for new ways of making animal welfare relevant in this context in order to support consumers in moving towards products with high standards of animal welfare.
The storm of the century! Promoting student enthusiasm for applied statistics
Authors: Fawcett Lee , Newman Keith
Published: September 2016

This article describes a hands‐on activity that has been used with students aged 12–18 years to promote the study of Statistics. We believe there is evidence to suggest an increase in student enthusiasm for Statistics at school, within the Mathematics curriculum, but also within other subjects such as Geography. We also believe that the use of such activities has resulted in some students giving more serious thought to studying Statistics at University. The activity described here is supported with a web‐based application to allow younger or less experienced students to engage with the material.
Amyloid Beta Influences Vascular Smooth Muscle Contractility and Mechanoadaptation
Authors: Hald Eric S. , Timm Connor D. , Alford Patrick W.
Published: September 2016

Amyloid beta accumulation in neuronal and cerebrovascular tissue is a key precursor to development of Alzheimer's disease and can result in neurodegeneration. While its persistence in Alzheimer's cases is well-studied, amyloid beta's direct effect on vascular function is unclear. Here, we measured the effect of amyloid beta treatment on vascular smooth muscle cell functional contractility and modeled the mechanoadaptive growth and remodeling response to these functional perturbations. We found that the amyloid beta 1-42 isoform induced a reduction in vascular smooth muscle cell mechanical output and reduced response to vasocontractile cues. These data were used to develop a thin-walled constrained mixture arterial model that suggests vessel growth, and remodeling in response to amyloid betamediated alteration of smooth muscle function leads to decreased ability of cerebrovascular vessels to vasodilate. These findings provide a possible explanation for the vascular injury and malfunction often associated with the development of neurodegeneration in Alzheimer's disease.
Dynamic Instability of Two Elastic Half-Spaces Sliding With a Rate-and-State Friction Constitutive Law
Authors: Colin Jérôme
Published: September 2016

The destabilization of the steady-state regime of two semi-infinite half-spaces of different elastic coefficients sliding upon each other has been theoretically investigated when a rate-and-state friction constitutive law controls the sliding. In the framework of linear and isotropic elastodynamics, the effect of the frictional constitutive law has been investigated onto the development of self-excited oscillations as well as the influence of the shear modulus difference between the two materials. The possibility of existence of a stick–slip regime and the conditions for the loss-of-contact are finally discussed.
A Compressive-Mode Wideband Vibration Energy Harvester Using a Combination of Bistable and Flextensional Mechanisms
Authors: Zou Hong-Xiang , Zhang Wen-Ming , Wei Ke-Xiang , Li Wen-Bo , Peng Zhi-Ke , Meng Guang
Published: September 2016

In this paper, a compressive-mode wideband vibration energy harvester using a combination of bistable and flextensional mechanisms is proposed. The structure consists of a cantilever with a magnet fixed at its free end, and a flextensional actuator with a magnet fixed at its free end. A theoretical model is developed to characterize the compressive-mode wideband vibration energy harvester. Both simulations and experiments are carried out to validate the design and analysis of the compressive-mode wideband vibration energy harvester. The results show that the device can work in broadband, and the piezoelectric constant d31 can be enlarged 134 times. The experimental results also indicate that the harvester can generate the power about 31 μW with the resistive load 390 kΩ, while the magnetic pressure is 2.9 N. A developed design including two flextensional actuators symmetrically arranged is also presented. The experimental results show that the two flextensional actuators in the developed design can harvest more energy than one flextensional actuator in the primal design.
Magnetic Shape Memory Micropump for Submicroliter Intracranial Drug Delivery in Rats
Authors: Barker Samuel , Rhoads Eric , Lindquist Paul , Vreugdenhil Martin , Müllner Peter
Published: September 2016

Point-of-care diagnostic devices, micrototal analysis (μTAS) systems, lab-on-a-chip development, and biomedical research rely heavily upon microfluidic management and innovative micropump design. Here, we describe the design and prototype deployment of a magnetic shape memory (MSM) micropump capable of submicroliter per minute flow rates. The pump contains no valves or moving parts in the fluid channel and is capable of bidirectional fluid transport. This pump was employed as the mechanism to deliver small intracranial dosages of ketamine and tetrodotoxin (TTX) at 0.33 μl/min during in vivo electrophysiological recordings in anesthetized rats, performing to required specifications.
Geometric Error Effects on Manipulators' Positioning Precision: A General Analysis and Evaluation Method
Authors: Simas Henrique , Di Gregorio Raffaele
Published: September 2016

Manufacturing and assembly (geometric) errors affect the positioning precision of manipulators. In six degrees-of-freedom (6DOF) manipulators, geometric error effects can be compensated through suitable calibration procedures. This, in general, is not possible in lower-mobility manipulators. Thus, methods that evaluate such effects must be implemented at the design stage to determine both which workspace region is less affected by these errors and which dimensional tolerances must be assigned to match given positioning-precision requirements. In the literature, such evaluations are mainly tailored on particular architectures, and the proposed techniques are difficult to extend. Here, a general discussion on how to take into account geometric error effects is presented together with a general method to solve this design problem. The proposed method can be applied to any nonoverconstrained architecture. Eventually, as a case study, the method is applied to the analysis of the geometric error effects of the translational parallel manipulator (TPM) Triflex-II.
Determinate Design and Analytical Analysis of a Class of Symmetrical Flexure Guiding Mechanisms for Linear Actuators
Authors: Hao Guangbo
Published: September 2016

This paper designs and analyses a class of single-axis translational flexure guiding mechanisms for linear actuators. The proposed flexure mechanisms have symmetrical configurations to eliminate parasitic motion for better precision and can provide large stiffness in the constraint directions and low stiffness in the actuation direction. Each flexure linear mechanism is composed of identical wire beams uniformly distributed in two planes (perpendicular to the actuation direction) with the minimal number of over-constraints. Analytical (symbolic) models are derived to quickly reflect effects of different parameters on performance characteristics of the flexure mechanism, enabling dimensional synthesis of different types of mechanisms. An optimal, compact, and symmetrical, flexure linear mechanism design is finally presented and prototyped with focused discussions on its primary motion.
Investigation on Structural Behaviors of Reactor Pressure Vessel With the Effects of Critical Heat Flux and Internal Pressure
Authors: Mao Jianfeng , Zhu Jianwei , Bao Shiyi , Luo Lijia , Gao Zengliang
Published: September 2016

The so-called “in-vessel retention (IVR)” is a severe accident management strategy, which is widely adopted in most advanced nuclear power plants. The IVR mitigation is assumed to be able to arrest the degraded melting core and maintain the structural integrity of reactor pressure vessel (RPV) within a prescribed hour. Essentially, the most dangerous thermal–mechanical loads can be specified as the combination of critical heat flux (CHF) and internal pressure. The CHF is the coolability limits of RPV submerged in water (∼150 °C) and heated internally (∼1327 °C), it results in a sudden transition of boiling crisis from nucleate to film boiling. Accordingly, from a structural integrity perspective, the RPV failure mechanisms span a wide range of structural behaviors, such as melt-through, creep damage, plastic deformation as well as thermal expansion. Furthermore, the geometric discontinuity of RPV created by the local material melting on the inside aggravates the stress concentration. In addition, the internal pressure effect that usually neglected in the traditional concept of IVR is found to be having a significant impact on the total damage evolution, as indicated in the Fukushima accident that a certain pressure (up to 8.0 MPa) still existed inside the RPV. This paper investigates structural behaviors of RPV with the effects of CHF and internal pressure. In achieving this goal, a continuum damage mechanics (CDM) based on the “ductility exhaustion” is adopted for the in-depth analysis.
Optimizing Energy Consumption in a Decentralized Manufacturing System
Authors: Ilsen Rebecca , Meissner Hermann , Aurich Jan C.
Published: September 2016

The deployment of modern information and communication technologies (ICT) within manufacturing systems leads to the creation of so-called cyber-physical production systems that consist of intelligent interconnected production facilities. One of the expected features of cyber-physical production systems is found to be the capability of self-organization and decentralized process planning in manufacturing. The functionality as well as the benefit of such self-organization concepts is yet to be proved. In this paper, the implementation of a virtual test field for the simulation of manufacturing systems based on a multi-agent system modeling concept is presented and used to evaluate a concept of decentralized process planning. Thereby, special focus is laid on the impact on energy consumption. The simulation results show the potential for energy reduction in manufacturing by a decentralized process-planning concept and yields hints for further development of such concepts.
Impact to Composite Box Containing Water and Baffles
Authors: Kwon Y. W. , South T. J. , Yun K. J.
Published: September 2016

A series of experimental tests were conducted for low-velocity impact on a composite box containing water in order to study the fluid–structure interaction (FSI). Then, baffles were inserted in the box to examine their effect on the structural response of the composite box. Finally, a computational study was conducted to supplement the experimental study. The water level inside the composite box was varied incrementally from 0% (i.e., no water) to 100% (full water). The impact velocity was also changed. In the experimental study, strain gauges and the load cell were used to measure the strain responses at the front, side, and back surfaces as well as the impact force. The results showed that the FSI effect was significant to the structural responses depending on the water level. The effect of the baffle was different among the front, side, and back surfaces. Both experimental and numerical results agreed well.
Improvement in Material Flow During Nonisothermal Warm Deep Drawing of Nonheat Treatable Aluminum Alloy Sheets
Authors: Panicker Sudhy S. , Kumar Panda Sushanta
Published: September 2016

Automotive industries are very much interested in implementing warm forming technology for fabrication of light weight auto-body panels using aluminum alloys without localized thinning or splitting. A nonheat treatable and low formable AA5754-H22 aluminum alloy sheet was selected in the present work, and a laboratory scale warm deep drawing test set-up and process sequences were designed to improve material flow through independent heating of punch and dies. Significant enhancement in cup depth was observed when the temperature of punch and dies were set to 30 °C and 200 °C, respectively. Thermo-mechanical finite-element (FE) model of the nonisothermal deep drawing test was developed successfully to study the improvement in material flow incorporating Barlat-89 yield theory using temperature dependent anisotropy coefficients and Cowper–Symonds hardening model. It was found that a nonisothermal temperature gradient of approximately 93 °C was established within the blank from the center to flange at the start of deformation, and subsequent evolution of temperature gradient helped in improving material flow into the die cavity. The effect of temperature gradient on forming behavior in terms of cup height, ear profile, and thinning development across flange, cup wall, and blank center were predicted and validated with experimental results.
Experimental and Computational Fluid Dynamics Studies on Dehumidifier in a Combined Cooling and Desalination Plant
Authors: Marale Suraj , Chiranjeevi C. , Srinivas T. , ThundilKaruppa Raj R.
Published: September 2016

Humidification–dehumidification (HDH) desalination is a simple technique to produce desalinated water from saline water. Dehumidifier is a key component in the HDH system, which influences the desalination yield. In the current work, a three-dimensional multiphase numerical simulation study is carried out on third dehumidifier alone to evaluate its performance using computational fluid dynamics (CFD) code. The simulation result is validated with experimental readings, and it is found that there exists a very close agreement between the predicted and the experimental readings. The key parameters influencing the dehumidifier performance are chilled water temperature, humid air temperature, and volume fraction. Experiments are carried out on the combined two stage HDH plant at different hot water temperature and flow rates. A detailed study of dehumidification process is carried out using ansys cfx 15.0 tool by solving the governing equations, namely, mass, momentum, and energy, with turbulence modeled through shear stress transport (SST) k–ω model of closure. Multiphase is solved using a free-surface multiphase model. The measured average cooled air temperature and relative humidity (RH) at the exit of third dehumidifier are 21 °C and 67%. The desalinated water produced at a hot water flow of 100 LPH is found as 2205 ml/h from the experiments. The CFD results are deviated by 0.41%, 6.45%, and −0.70% with that of experimental results at the dehumidifier for air temperature, velocity, and chilled water temperature, respectively.
Active control of scattered acoustic fields: Cancellation, reproduction and cloaking
Authors: Cheer Jordan
Published: September 2016

The active control of sound fields has been widely applied in both active noise control and sound field reproduction, however, relatively few studies have focused on active acoustic cloaking. In order to build upon the knowledge and understanding in the areas of active noise control and sound field reproduction, this paper investigates the corresponding physical limitations and compares them to the active cloaking problem when the three strategies are employed in the presence of an acoustic scatterer. The three sound field control strategies have been formulated within a consistent framework, and this has enabled insight into the physical control mechanisms. Two different three-dimensional scattering problems have then been simulated and used to investigate the performance limitations of the three strategies. The influence of the number and proximity of control sources to the scattering object have been investigated, and it has been shown that the requirements for active cloaking differ from those for active noise control and sound field reproduction. Specifically, it has been shown that there is a clear distinction between controlling the internal and external sound fields in the three cases.
Room temperature stable CO

x

-free H
2
production from methanol with magnesium oxide nanophotocatalysts
Authors: Liu Zhengqing , Yin Zongyou , Cox Casandra , Bosman Michel , Qian Xiaofeng , Li Na , Zhao Hongyang , Du Yaping , Li Ju , Nocera Daniel G.
Published: September 2016

A novel facile strategy was developed to synthesize MgO nanocrystals for producing H
2
through photodecomposing methanol.
Portraying breast cancers with long noncoding RNAs
Authors: Van Grembergen Olivier , Bizet Martin , de Bony Eric J. , Calonne Emilie , Putmans Pascale , Brohée Sylvain , Olsen Catharina , Guo Mingzhou , Bontempi Gianluca , Sotiriou Christos , Defrance Matthieu , Fuks François
Published: September 2016

Comprehensive analysis of the lncRNA landscape in breast cancers and its relationship with key clinical features and functional pathways.
Genomic and Transcriptional Mapping of PaMx41, Archetype of a New Lineage of Bacteriophages Infecting Pseudomonas aeruginosa
Authors: Cruz-Plancarte Indira , Cazares Adrián , Guarneros Gabriel
Published: September 2016

Previously, a collection of virulent phages infecting
Pseudomonas aeruginosa
was isolated from open water reservoirs and residual waters. Here, we described the comparative genomics of a set of five related phages from the collection, the physical structure of the genome, the structural proteomics of the virion, and the transcriptional program of archetypal phage PaMx41. The phage genomes were closely associated with each other and with those of two other
P. aeruginosa
phages, 119X and PaP2, which were previously filed in the databases. Overall, the genomes were approximately 43 kb, harboring 53 conserved open reading frames (ORFs) and three short ORFs in indel regions and containing 45% GC content. The genome of PaMx41 was further characterized as a linear, terminally redundant DNA molecule. A total of 16 ORFs were associated with putative functions, including nucleic acid metabolism, morphogenesis, and lysis, and eight virion proteins were identified through mass spectrometry. However, the coding sequences without assigned functions represent 70% of the ORFs. The PaMx41 transcription program was organized in early, middle, and late expressed genomic modules, which correlated with regions containing functionally related genes. The high genomic conservation among these distantly isolated phages suggests that these viruses undergo selective pressure to remain unchanged. The 119X lineage represents a unique set of phages that corresponds to a novel phage group. The features recognized in the genomes and the broad host range of clinical strains suggest that these phages are candidates for therapy applications.

IMPORTANCE
Pseudomonas aeruginosa
is an opportunistic pathogen that causes stubborn nosocomial infections that are frequently resistant to multiple antibiotics. Bacterial viruses (bacteriophages or phages) represent a natural mechanism for pathogenic bacterial control. Here, a group of virulent phages, previously shown to infect a broad range of clinical
P. aeruginosa
strains, was characterized at the genomic and molecular levels. These phages belong to a unique and tightly related group. In addition, we conducted a transcriptional study of an archetypal phage of this group to characterize the role of many unknown coding sequences based on expression temporalities. These results contribute to our knowledge of 119X-like phages and, in general, provide information concerning
P. aeruginosa
podophage diversity and lytic cycles.
Effects of Proton Pump Inhibitors on the Gastric Mucosa-Associated Microbiota in Dyspeptic Patients
Authors: Paroni Sterbini Francesco , Palladini Alessandra , Masucci Luca , Cannistraci Carlo Vittorio , Pastorino Roberta , Ianiro Gianluca , Bugli Francesca , Martini Cecilia , Ricciardi Walter , Gasbarrini Antonio , Sanguinetti Maurizio , Cammarota Giovanni , Posteraro Brunella
Published: September 2016

Besides being part of anti-
Helicobacter pylori
treatment regimens, proton pump inhibitors (PPIs) are increasingly being used to treat dyspepsia. However, little is known about the effects of PPIs on the human gastric microbiota, especially those related to
H. pylori
infection. The goal of this study was to characterize the stomach microbial communities in patients with dyspepsia and to investigate their relationships with PPI use and
H. pylori
status. Using 16S rRNA gene pyrosequencing, we analyzed the mucosa-associated microbial populations of 24 patients, of whom 12 were treated with the PPI omeprazole and 9 (5 treated and 4 untreated) were positive for
H. pylori
infection. The
Proteobacteria
,
Firmicutes
,
Bacteroidetes
,
Fusobacteria
, and
Actinobacteria
phyla accounted for 98% of all of the sequences, with
Helicobacter
,
Streptococcus
, and
Prevotella
ranking among the 10 most abundant genera.
H. pylori
infection or PPI treatment did not significantly influence gastric microbial species composition in dyspeptic patients. Principal-coordinate analysis of weighted UniFrac distances in these communities revealed clear but significant separation according to
H. pylori
status only. However, in PPI-treated patients,
Firmicutes
, particularly
Streptococcaceae
, were significantly increased in relative abundance compared to those in untreated patients. Consistently,
Streptococcus
was also found to significantly increase in relation to PPI treatment, and this increase seemed to occur independently of
H. pylori
infection. Our results suggest that
Streptococcus
may be a key indicator of PPI-induced gastric microbial composition changes in dyspeptic patients. Whether the gastric microbiota alteration contributes to dyspepsia needs further investigation.

IMPORTANCE
Although PPIs have become a popular treatment choice, a growing number of dyspeptic patients may be treated unnecessarily. We found that patients treated with omeprazole showed gastric microbial communities that were different from those of untreated patients. These differences regarded the abundances of specific taxa. By understanding the relationships between PPIs and members of the gastric microbiota, it will be possible to envisage new strategies for better managing patients with dyspepsia.
The Core Gut Microbiome of the American Cockroach, Periplaneta americana, Is Stable and Resilient to Dietary Shifts
Authors: Tinker Kara A. , Ottesen Elizabeth A.
Published: September 2016

The omnivorous cockroachPeriplaneta americanahosts a diverse hindgut microbiota encompassing hundreds of microbial species. In this study, we used 16S rRNA gene sequencing to examine the effect of diet on the composition of theP. americanahindgut microbial community. Results show that the hindgut microbiota ofP. americanaexhibit a highly stable core microbial community with low variance in compositions between individuals and minimal community change in response to dietary shifts. This core hindgut microbiome is shared between laboratory-hosted and wild-caught individuals, although wild-caught specimens exhibited a higher diversity of low-abundance microbes that were lost following extended cultivation under laboratory conditions. This taxonomic stability strongly contrasts with observations of the gut microbiota of mammals, which have been shown to be highly responsive to dietary change. A comparison ofP. americanahindgut samples with human fecal samples indicated that the cockroach hindgut community exhibited higher alpha diversity but a substantially lower beta diversity than the human gut microbiome. This suggests that cockroaches have evolved unique mechanisms for establishing and maintaining a diverse and stable core microbiome.

IMPORTANCEThe gut microbiome plays an important role in the overall health of its host. A healthy gut microbiota typically assists with defense against pathogens and the digestion and absorption of nutrients from food, while dysbiosis of the gut microbiota has been associated with reduced health. In this study, we examined the composition and stability of the gut microbiota from the omnivorous cockroachPeriplaneta americana.We found thatP. americanahosts a diverse core gut microbiome that remains stable after drastic long-term changes in diet. While other insects, notably ant and bee species, have evolved mechanisms for maintaining a stable association with specific gut microbiota, these insects typically host low-diversity gut microbiomes and consume specialized diets. In contrast,P. americanahosts a gut microbiota that is highly species rich and consumes a diverse solid diet, suggesting that cockroaches have evolved unique mechanisms for developing and maintaining a stable gut microbiota.
Stress-Induced Evolution of Heat Resistance and Resuscitation Speed in Escherichia coli O157:H7 ATCC 43888
Authors: Gayán Elisa , Cambré Alexander , Michiels Chris W. , Aertsen Abram
Published: September 2016

The development of resistance in foodborne pathogens to food preservation techniques is an issue of increasing concern, especially in minimally processed foods where safety relies on hurdle technology. In this context, mild heat can be used in combination with so-called nonthermal processes, such as high hydrostatic pressure (HHP), at lower individual intensities to better retain the quality of the food. However, mild stresses may increase the risk of (cross-)resistance development in the surviving population, which in turn might compromise food safety. In this investigation, we examined the evolution of
Escherichia coli
O157:H7 strain ATCC 43888 after recurrent exposure to progressively intensifying mild heat shocks (from 54.0°C to 60.0°C in 0.5°C increments) with intermittent resuscitation and growth of survivors. As such, mutant strains were obtained after 10 cycles of selection with ca. 10
6
-fold higher heat resistance than that for the parental strain at 58.0°C, although this resistance did not extend to temperatures exceeding 60.0°C. Moreover, these mutant strains typically displayed cross-resistance against HHP shock and displayed signs of enhanced RpoS and RpoH activity. Interestingly, additional cycles of selection maintaining the intensity of the heat shock constant (58.5°C) selected for mutant strains in which resuscitation speed, rather than resistance, appeared to be increased. Therefore, it seems that resistance and resuscitation speed are rapidly evolvable traits in
E. coli
ATCC 43888 that can compromise food safety.

IMPORTANCE
In this investigation, we demonstrated that
Escherichia coli
O157:H7 ATCC 43888 rapidly acquires resistance to mild heat exposure, with this resistance yielding cross-protection to high hydrostatic pressure treatment. In addition, mutants of
E. coli
ATCC 43888 in which resuscitation speed, rather than resistance, appeared to be improved were selected. As such, both resistance and resuscitation speed seem to be rapidly evolvable traits that can compromise the control of foodborne pathogens in minimal processing strategies, which rely on the efficacy of combined mild preservation stresses for food safety.
Aphid Infestation Increases Fusarium langsethiae and T-2 and HT-2 Mycotoxins in Wheat
Authors: Drakulic Jassy , Ajigboye Olubukola , Swarup Ranjan , Bruce Toby , Ray Rumiana V.
Published: September 2016

Fusarium langsethiae
is a fungal pathogen of cereal crops that is an increasing problem in northern Europe, but much of its epidemiology is poorly understood. The species produces the mycotoxins T-2 and HT-2, which are highly toxic. It was hypothesized that grain aphids,
Sitobion avenae
, may transmit
F. langsethiae
inoculum between wheat plants, and a series of transmission experiments and volatile chemical analyses was performed to test this. Manual translocation of aphids from inoculated to uninfected hosts resulted in pathogen DNA accumulation in hosts. However, the free movement of wingless aphids from infected to healthy plants did not. The addition of winged aphids reared on
F. langsethiae
-inoculated wheat seedlings to wheat plants also did not achieve successful pathogen transfer. While our data suggested that aphid transmission of the pathogen was not very efficient, we observed an increase in disease when aphids were present. After seedling inoculation, an increase in pathogen DNA accumulation in seedling leaves was observed upon treatment with aphids. Furthermore, the presence of aphids on wheat plants with
F. langsethiae-
inoculated ears not only led to a rise in the amount of
F. langsethiae
DNA in infected grain but also to an increase in the concentrations of T-2 and HT-2 toxins, with more than 3-fold higher toxin levels than diseased plants without aphids. This work highlights that aphids increase the susceptibility of wheat host plants to
F. langsethiae
and that aphid infestation is a risk factor for accumulating increased levels of T-2 and HT-2 in wheat products.

IMPORTANCE
Fusarium langsethiae
is shown here to cause increased contamination levels of grain with toxins produced by fungus when aphids share the host plant. This effect has also recently been demonstrated with
Fusarium graminearum
, yet the two fungal species show stark differences in their effect on aphid populations. In both cases, aphids improve the ability of the pathogens to cause and initiate
Fusarium
head blight (FHB) disease in wheat, but
F. langsethiae
may be able to act as a dispersal agent.
F. langsethiae
contributes harmful toxins to wheat grain that need to be controlled, but as yet, its epidemiology is unresolved. This work reveals insights into the role aphids play in promoting the successful colonization of this species in wheat and the benefit of controlling aphid populations on crops that are at high risk of FHB.
Ixodes persulcatus Ticks as Vectors for the Babesia microti U.S. Lineage in Japan
Authors: Zamoto-Niikura Aya , Morikawa Shigeru , Hanaki Ken-Ichi , Holman Patricia J. , Ishihara Chiaki
Published: September 2016

The U.S. lineage, one of the major clades in theBabesia microtigroup, is known as a causal agent of human babesiosis mostly in the northeastern and upper midwestern United States. This lineage, however, also is distributed throughout the temperate zone of Eurasia with several reported human cases, although convincing evidence of the identity of the specific vector(s) in this area is lacking. Here, the goal was to demonstrate the presence of infectious parasites directly in salivary glands ofIxodes persulcatus, from which U.S. lineage genetic sequences have been detected in Asia, and to molecularly characterize the isolates. Five PCR-positive specimens were individually inoculated into hamsters, resulting in infections in four; consequently, four strains were newly established. Molecular characterization, including 18S rRNA, β-tubulin, andCCT7gene sequences, as well as Western blot analysis and indirect fluorescent antibody assay, revealed that all four strains were identical to each other and to the U.S. lineage strains isolated from rodents captured in Japan. The 18S rRNA gene sequence from the isolates was identical to those fromI. persulcatusin Russia and China, but the genetic and antigenic profiles of the Japanese parasites differ from those in the United States and Europe. Together with previous epidemiological and transmission studies, we conclude thatI. persulcatusis likely the principal vector for theB. microtiU.S. lineage in Japan and presumably in northeastern Eurasia.

IMPORTANCEThe major cause of human babesiosis, the tick-borne blood parasiteBabesia microti, U.S. lineage, is widely distributed in the temperate Northern Hemisphere. However, the specific tick vector(s) remains unidentified in Eurasia, where there are people with antibodies to theB. microtiU.S. lineage and cases of human babesiosis. In this study, the first isolation ofB. microtiU.S. lineage fromIxodes persulcatusticks, a principal vector for many tick-borne diseases, is described in Japan. Limited antigenic cross-reaction was found between the Japan and United States isolates. Thus, current serological tests based on U.S. isolates may underestimateB. microtioccurrence outside the United States. This study and previous studies indicate thatI. persulcatusis part of theB. microtiU.S. lineage life cycle in Japan and, presumably, northeastern Eurasia. This report will be important for public health, especially since infection may occur through transfusion, and also to researchers in the field of parasitology.
Long-term effects of adenotonsillectomy in children with obstructive sleep apnoea: protocol for a systematic review
Authors: Damiani Felipe , Rada Gabriel , Gana Juan Cristóbal , Brockmann Pablo E , Alberti Gigliola
Published: September 2016

Introduction

Adenotonsillar hypertrophy is the most important anatomical factor associated with obstructive sleep apnoea syndrome in children. The American Academy of Pediatrics recommends adenotonsillectomy as the first line of treatment. AT can reduce the apnoea hypopnoea index; however, its effect on long-term outcomes remains unclear.

Methods and analysis

We will conduct an electronic search for randomised controlled trials in MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL) and EMBASE. We will also identify literature by reviewing the references included in the selected studies and relevant reviews, screening through important scientific conferences, and searching for ongoing trials in the WHO International Clinical Trials Registry Platform. Two researchers will independently undertake selection of studies, data extraction and assessment of the risk of bias of included studies. We will estimate pooled risk ratios for dichotomous data, and mean difference or standardised mean difference for continuous outcomes. A random-effects model will be used for meta-analyses. Data synthesis and other analyses will be conducted using RevMan V.5.3 software.

Ethics and dissemination

No ethics approval is considered necessary. The results of this study will be disseminated via peer-reviewed publications and social networks.

Trial registration number

CRD42015022102.
Influence of habitual dietary fibre intake on the responsiveness of the gut microbiota to a prebiotic: protocol for a randomised, double-blind, placebo-controlled, cross-over, single-centre study
Authors: Lunken Genelle , Brough Louise , Butts Chrissie , Murphy Rinki , Whelan Kevin , Coad Jane
Published: September 2016

Introduction

The commensal gut microbiota have been shown to have an impact on human health as aberrant gut microbiota have been linked to disease. Dietary constituents are influential in shaping the gut microbiota. Diet-specific therapeutic strategies may therefore play a role in optimising human health via beneficial manipulation of the gut microbiota. Research has suggested that an individual's baseline gut microbiota composition may influence how the gut microbiota respond to a dietary intervention and individuals with differing habitual dietary intakes appear to have distinct baseline gut microbiota compositions. The responsiveness of the gut microbiota may therefore be influenced by habitual dietary intakes. This study aims to investigate what influence differing habitual dietary fibre intakes have on the responsiveness of the gut microbiota to a prebiotic intervention.

Methods and analysis

In this randomised, double-blind, placebo-controlled, cross-over, single-centre study, 20 low dietary fibre (dietary fibre intake <18 g/day for females and <22 g/day for males) and 20 high dietary fibre (dietary fibre intake ≥25 g/day for females and ≥30 g/day for males) consumers will be recruited. Participants will be randomised to a placebo (Glucidex 29 Premium) or a prebiotic (Synergy 1) intervention for 3 weeks with a 3-week washout followed by 3 weeks of the alternative intervention. Outcome measures of gut microbiota composition (using 16S rRNA gene sequencing) and functional capacity (faecal short chain fatty acid concentrations and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt)) as well as appetite (visual analogue scale appetite questionnaire) will be assessed at the beginning and end of each intervention phase.

Ethics and dissemination

The Massey University Human Ethics Committee approved this study (Massey University HEC: Southern A application—15/34). Results will be disseminated through peer-review journal publications, conference presentations and a summary of findings will be distributed to participants.

Trial registration number

ACTRN12615000922572; Pre-results.
Association between progression-free survival and health-related quality of life in oncology: a systematic review protocol
Authors: Kovic Bruno , Guyatt Gordon , Brundage Michael , Thabane Lehana , Bhatnagar Neera , Xie Feng
Published: September 2016

Introduction

There is an increasing number of new oncology drugs being studied, approved and put into clinical practice based on improvement in progression-free survival, when no overall survival benefits exist. In oncology, the association between progression-free survival and health-related quality of life is currently unknown, despite its importance for patients with cancer, and the unverified assumption that longer progression-free survival indicates improved health-related quality of life. Thus far, only 1 study has investigated this association, providing insufficient evidence and inconclusive results. The objective of this study protocol is to provide increased transparency in supporting a systematic summary of the evidence bearing on this association in oncology.

Methods and analysis

Using the OVID platform in MEDLINE, Embase and Cochrane databases, we will conduct a systematic review of randomised controlled human trials addressing oncology issues published starting in 2000. A team of reviewers will, in pairs, independently screen and abstract data using standardised, pilot-tested forms. We will employ numerical integration to calculate mean incremental area under the curve between treatment groups in studies for health-related quality of life, along with total related error estimates, and a 95% CI around incremental area. To describe the progression-free survival to health-related quality of life association, we will construct a scatterplot for incremental health-related quality of life versus incremental progression-free survival. To estimate the association, we will use a weighted simple regression approach, comparing mean incremental health-related quality of life with either median incremental progression-free survival time or the progression-free survival HR, in the absence of overall survival benefit.

Discussion

Identifying direction and magnitude of association between progression-free survival and health-related quality of life is critically important in interpreting results of oncology trials. Systematic evidence produced from our study will contribute to improvement of patient care and practice of evidence-based medicine in oncology.
Discrepancies between patient-reported outcomes, and endoscopic and histological appearance in UC
Authors: Colombel Jean-Frédéric , Keir Mary E , Scherl Alexis , Zhao Rui , de Hertogh Gert , Faubion William A , Lu Timothy T
Published: September 2016

Objective

Both endoscopy and histology may be included in the definition of mucosal healing in UC. This study aimed to establish the association between patient-reported outcomes, specifically symptom measures, and the presence of inflammation as measured by endoscopy and histology in UC.

Design

Using patient data from an observational multicentre study of UC (n=103), rectal bleeding (RB) and stool frequency (SF) symptom subscores of the Mayo Clinic Score (MCS) were compared with the endoscopic subscore (MCSe) and histology. Faecal calprotectin and biopsy cytokine expression were also evaluated.

Results

When identifying UC patients with inactive disease, RB scores were superior to SF scores and the combination (sensitivity/specificity: MCSe=0/1, RB 77%/81%, SF 62%/95%, RB+SF 54%/95%; MCSe=0, RB 87%/66%, SF 76%/83%, RB+SF 68%/86%). Across different definitions of mucosal healing (MCSe≤1; 0; or 0 plus inactive histology), a larger subset of patients reported increased SF (39%, 25% and 27%, respectively) compared with RB (24%, 13% and 10%). Faecal calprotectin and inflammatory cytokine expression were higher in patients with active disease compared with patients with mucosal healing, but there were no differences between patients using increasingly stringent definitions of mucosal healing.

Conclusions

Endoscopically inactive disease is associated with absence of RB but not with complete normalisation of SF. Achieving histological remission did not improve symptomatic relief. In addition, in these patients, higher inflammatory biomarker levels were not observed. These data suggest that non-inflammatory changes, such as bowel damage, may contribute to SF in UC.
Temperature-dependent inotropic and lusitropic indices based on half-logistic time constants for four segmental phases in isovolumic left ventricular pressure–time curve in excised, cross-circulated canine heart
Authors: Mizuno Ju , Mohri Satoshi , Yokoyama Takeshi , Otsuji Mikiya , Arita Hideko , Hanaoka Kazuo
Published: September 2016

Varying temperature affects cardiac systolic and diastolic function and the left ventricular (LV) pressure–time curve (PTC) waveform that includes information about LV inotropism and lusitropism. Our proposed half-logistic (h-L) time constants obtained by fitting using h-L functions for four segmental phases (Phases I–IV) in the isovolumic LV PTC are more useful indices for estimating LV inotropism and lusitropism during contraction and relaxation periods than the mono-exponential (m-E) time constants at normal temperature. In this study, we investigated whether the superiority of the goodness of h-L fits remained even at hypothermia and hyperthermia. Phases I–IV in the isovolumic LV PTCs in eight excised, cross-circulated canine hearts at 33, 36, and 38 °C were analyzed using h-L and m-E functions and the least-squares method. The h-L and m-E time constants for Phases I–IV significantly shortened with increasing temperature. Curve fitting using h-L functions was significantly better than that using m-E functions for Phases I–IV at all temperatures. Therefore, the superiority of the goodness of h-L fit vs. m-E fit remained at all temperatures. As LV inotropic and lusitropic indices, temperature-dependent h-L time constants could be more useful than m-E time constants for Phases I–IV.