bluuebunny/crossref_metadata_2025 huggingface dataset:
An
ompR-envZ
Two-Component System Ortholog Regulates Phase Variation, Osmotic Tolerance, Motility, and Virulence in Acinetobacter baumannii Strain AB5075
Authors: Tipton Kyle A. , Rather Philip N.
Published: November 2016

Recently, a novel phase-variable colony opacity phenotype was discovered in
Acinetobacter baumannii
strain AB5075, where colonies interconvert between opaque and translucent variants. Opaque colonies become mottled or sectored after 24 h of growth due to translucent variants arising within the colony. This easily distinguishable opaque-colony phenotype was used to screen for random transposon insertions that increased the frequency of sectoring at a time point when wild-type colonies were uniformly opaque. A colony was identified that contained multiple papillae of translucent variants, and the insertion in this mutant mapped to an ortholog of the two-component system response regulator
ompR
. Subsequent investigation of in-frame deletions of
ompR
and the sensor kinase
envZ
(located adjacent to
ompR
) showed that the switching frequency from opaque to translucent was increased 401- and 281-fold, respectively. The
ompR
mutant also exhibited sensitivity to sodium chloride in growth medium, whereas the
envZ
mutation did not elicit sensitivity to sodium chloride. Mutation of either gene reduced motility in
A. baumannii
strain AB5075, but a mutation in both
ompR
and
envZ
produced a more profound effect. The
ompR
and
envZ
genes were cotranscribed but were not subject to autoregulation by OmpR. Both
ompR
and
envZ
mutant opaque variants were attenuated in virulence in the
Galleria mellonella
infection model, whereas mutation of
ompR
had no effect on the virulence of the translucent variant.

IMPORTANCE
Acinetobacter baumannii
is a well-known antibiotic-resistant pathogen; many clinical isolates can only be treated by a very small number of antibiotics (including colistin), while some exhibit panresistance. The current antimicrobial arsenal is nearing futility in the treatment of
Acinetobacter
infections, and new avenues of treatment are profoundly needed. Since phase variation controls the transition between opaque (virulent) and translucent (avirulent) states in
A. baumannii
, this may represent an “Achilles' heel” that can be targeted via the development of small molecules that lock cells in the translucent state and allow the host immune system to clear the infection. A better understanding of how phase variation is regulated may allow for the development of methods to target this process. The
ompR-envZ
two-component system ortholog negatively regulates phase variation in
A. baumannii
, and perturbation of this system leads to the attenuation of virulence in an invertebrate infection model.
High-precision time-space correlation through coupled apatite and zircon tephrochronology: An example from the Permian-Triassic boundary in South China
Authors: Baresel Björn , d’Abzac François-Xavier , Bucher Hugo , Schaltegger Urs
Published: November 2016

Accurate and precise dating of individual volcanogenic beds that spread across multiple sedimentary successions is a powerful tool to untangle stratigraphic age contradictions, since these horizons are deposited synchronously. In this study, we show that combining apatite chemistry with zircon age, Th/U ratio, and Hf isotope composition leads to reliable lateral correlation of volcanic horizons across sections representing disparate biological, chemical, and physical paleoenvironments. We correlate two volcanogenic horizons across six sedimentary sections straddling the Permian-Triassic boundary (PTB) in the Nanpanjiang Basin (South China), including the last Permian bed below the unconformity in shallow-water sections of the Luolou Platform. We place the PTB in our sections at the marked lithological change in order to avoid the difficulties that arise from the diachronism of the index conodont Hindeodus parvus, the first occurrence of which defines the PTB at the Global Stratotype Section and Point at Meishan. Our new data demonstrate that these volcanogenic beds are contemporaneous and cogenetic, allowing us to pool high-precision U-Pb zircon ages from the same horizon across several sections, and dating the last Permian volcanic event in this basin at 252.048 ± 0.033 Ma. We show that the mineral chemistry of apatite and zircon of intra- and interbasin-wide volcanogenic beds provides tie points against which biozones, carbon isotopes, astronomic cycles, and geomagnetic polarity time series can be stringently tested.
40Ar/39Ar dating and thermal modeling of adularia to constrain the timing of hydrothermal activity in magmatic settings
Authors: Oze Christopher , Cattell Hamish , Grove Marty
Published: November 2016

Hydrothermal systems develop via interspersed thermal events over tens to hundreds of thousands of years. The timing of how these systems evolve is commonly established via application of geochronology to a variety of phases and/or the indirect correlation of dated stratigraphy. Here we report 40Ar/39Ar results from adularia extracted from a single mineralized fracture in the late Quaternary Tauhara geothermal system of New Zealand. By utilizing both the age and Ar diffusion properties, we demonstrate how adularia can provide reliable temporal and thermal constraints on the evolution of geologically youthful and active geothermal systems. Our results indicate that adularia formation occurred after 30 ka (mean age 15 ± 10 ka), possibly resulting from subsurface fracturing induced by a 25.4 ka hydrothermal eruption. Simulation of transient heat effects upon Ar retention in adularia with respect to the thermal history of the Tauhara geothermal system confirm that this age is consistent with the time of adularia crystallization. Overall, 40Ar/39Ar dating on geologically young hydrothermal adularia with respect to its thermal history may be used to assess the timing and potential events (e.g., eruptions and fracturing) related to hydrothermal system evolution.
First direct evidence for natural occurrence of colloidal silica in chalcedony-hosted vacuoles and implications for ore-forming processes
Authors: Prokofiev Vsevolod Yu. , Kamenetsky Vadim S. , Selektor Sofia L. , Rodemann Thomas , Kovalenker Vladimir A. , Vatsadze Sergey Z.
Published: November 2016

Different forms of abundant silica (e.g., quartz and chalcedony) are closely associated with many types of ore deposits in igneous, metamorphic, and sedimentary environments. Occurrence of quartz and metal-bearing minerals together strongly indicates that silica is an important component in hydrothermal fluids transporting and concentrating economic metals to the ore grade, however chemical and physical characteristics of such ore-forming media remain debated. Understanding of the environment in which chalcedony forms is largely hampered by the lack of chalcedony-hosted fluid inclusions. Our study reports for the first time fortuitously preserved, large-sized (up to 150 μm) fluid inclusions in chalcedony from the Gonchak deposit of optical calcite in the Early Triassic basalts belonging to the Siberian large igneous province. The application of microthermometric methods, scanning electron microscopy with cathodoluminescence, and laser Raman spectroscopy to the fluid inclusions and their host chalcedony recognized the formation of chalcedony from a colloidal suspension. The fluid inclusions represent a gel-like saline aqueous fluid that is residual after precipitation of spherulitic chalcedony aggregates with numerous H2O-bearing and H2O-poor layers. We propose that the colloidal nature of fluids forming chalcedony lends strong support to the natural existence of experimentally predicted “silicothermal fluids”. Such fluids can be instrumental in mobilizing and transporting large quantities of both silica and nano- and micro-particles of ore minerals, followed by efficient separation of the latter from coagulating silica gel into ore-rich zones and bodies.
Pituitary dysfunction after traumatic brain injury: are there definitive data in children?
Authors: Casano-Sancho Paula
Published: November 2016

In the past decade, several studies in adults and children have described the risk of pituitary dysfunction after traumatic brain injury (TBI). As a result, an international consensus statement recommended follow-up on the survivors. This paper reviews published studies regarding hypopituitarism after TBI in children and compares their results. The prevalence of hypopituitarism ranges from 5% to 57%. Growth hormone (GH) and ACTH deficiency are the most common, followed by gonadotropins and thyroid-stimulating hormone. Paediatric studies have failed to identify risk factors for developing hypopituitarism, and therefore we have no tools to restrict screening in severe TBI. In addition, the present review highlights the lack of a unified follow-up and the fact that unrecognised pituitary dysfunction is frequent in paediatric population. The effect of hormonal replacement in patient recovery is important enough to consider baseline screening and reassessment between 6 and 12 months after TBI. Medical community should be aware of the risk of pituitary dysfunction in these patients, given the high prevalence of endocrine dysfunction already reported in the studies. Longer prospective studies are needed to uncover the natural course of pituitary dysfunction, and new studies should be designed to test the benefit of hormonal replacement in metabolic, cognitive and functional outcome in these patients.
Smooth muscle tumour of uncertain malignant potential (SMTUMP) in the nasal cavity: an incidental finding
Authors: Nayak Dipak Ranjan , Ghanpur Asheesh Dora , Reddy Apoorva N , Sharma Swati
Published: November 2016

Sino-nasal smooth muscle tumours of uncertain malignant potential (SMTUMP) are very rare neoplasms of mesenchymal origin with features in between a benign leiomyoma and a leiomyosarcoma. We report a rare case of SMTUMP in a 44-year-old woman, who presented with vague symptoms of pharyngitis. Nasal endoscopy revealed a smooth mass in left nasal cavity. Contrast-enhanced CT and MRI scans showed features likely to be inverted papilloma or olfactory neuroblastoma or meningioma. Excision was planned and intraoperatively, frozen section revealed a probable spindle cell lesion. Final histopathological report following immunohistochemistry (IHC) & immunofluoresence (IF) confirmed it to be a SMTUMP. This patient underwent complete resection via endoscopic KTP laser assisted, anterior skull base surgery with no recurrence on follow-up.
Unusual cause of profound weight loss in a young woman
Authors: Rastogi Ashu , Uppula Pavan , Mukherjee Kanchan Kumar , Bhansali Anil
Published: November 2016

A 27-year-old woman presented with anorexia, weight loss and psychiatric symptoms for the past 4 years. She did not have history of headache, visual disturbances or symptoms of raised intracranial pressure. She was sarcopenic with body mass index of 10.16 kg/m2.Her systemic examination was normal except for temporal hemianopia suggesting a sellar/suprasellar lesion. Hormonal evaluation revealed pan-hypopituitarism with central diabetes insipidus. Subsequent neuroimaging revealed sellar-suprasellar mass lesion with intense contrast enhancement and leptomeningeal metastases. Cerebrospinal fluid analysis showed elevated β human chorionic gonadotropin and the presence of syncytiotrophoblast germ cells. Histopathology from the mass lesion confirmed the diagnosis of germinoma. Immunohistochemistry of the tumour tissue was positive for c-kit and placental alkaline phosphatise. She received a combination of chemotherapy with craniospinal irradiation. Significant weight loss in a young woman may not always be an eating disorder like anorexia nervosa albeit more common than germ cell tumour.
Too much detention? Street Triage and detentions under Section 136 Mental Health Act in the North-East of England: a descriptive study of the effects of a Street Triage intervention
Authors: Keown Patrick , French Jo , Gibson Graham , Newton Eddy , Cull Steve , Brown Paul , Parry Jo , Lyons Diana , McKinnon Iain
Published: November 2016

Objectives

To describe the impact of Street Triage (ST) on the number and rate of Section 136 Mental Health Act (S136) detentions in one NHS Mental Health and Disability Trust (Northumberland, Tyne and Wear (NTW)).

Design

Comparative descriptive study of numbers and rates of S136 detentions prior to and following the introduction of ST in NTW. More detailed data were obtained from one local authority in the NTW area.

Setting

NTW, a secondary care NHS Foundation Trust providing mental health and disability services in the north-east of England, in conjunction with Northumbria Police Service.

Participants

People being detained under S136 Mental Health Act (MHA). Routine data on S136 detentions and ST interventions were obtained from NTW, Northumbria Police, Sunderland Hospitals NHS Foundation Trust and Sunderland Local Authority.

Interventions

Introduction of a ST service in NTW. The main outcome measures were routinely collected data on the number and rate of ST interventions as well as patterns of the numbers and rates of S136 detentions. These were collected retrospectively.

Results

The annual rate of S136 detentions reduced by 56% in the first year of ST (from 59.8 per 100 000 population to 26.4 per 100 000). There was a linear relationship between the rate of ST in each locality and the reduction in rate of S136 detentions. There were 1623 ST contacts in the first 3 localities to have a ST service during its first year; there were also 403 fewer S136 detentions. Data from Sunderland indicate a 78% reduction in S136 use and a significant reduction in the number and proportion of adult admissions that originated from S136 detentions.

Conclusions

There is evidence to support the hypothesis that ST decreases the rate of s136 detention. When operating across the whole of NTW, ST resulted in 50 fewer S136 detentions a month, which represents a substantial reduction.
Does integrated care reduce hospital activity for patients with chronic diseases? An umbrella review of systematic reviews
Authors: Damery Sarah , Flanagan Sarah , Combes Gill
Published: November 2016

Objective

To summarise the evidence regarding the effectiveness of integrated care interventions in reducing hospital activity.

Design

Umbrella review of systematic reviews and meta-analyses.

Setting

Interventions must have delivered care crossing the boundary between at least two health and/or social care settings.

Participants

Adult patients with one or more chronic diseases.

Data sources

MEDLINE, Embase, ASSIA, PsycINFO, HMIC, CINAHL, Cochrane Library (HTA database, DARE, Cochrane Database of Systematic Reviews), EPPI-Centre, TRIP, HEED, manual screening of references.

Outcome measures

Any measure of hospital admission or readmission, length of stay (LoS), accident and emergency use, healthcare costs.

Results

50 reviews were included. Interventions focused on case management (n=8), chronic care model (CCM) (n=9), discharge management (n=15), complex interventions (n=3), multidisciplinary teams (MDT) (n=10) and self-management (n=5). 29 reviews reported statistically significant improvements in at least one outcome. 11/21 reviews reported significantly reduced emergency admissions (15–50%); 11/24 showed significant reductions in all-cause (10–30%) or condition-specific (15–50%) readmissions; 9/16 reported LoS reductions of 1–7 days and 4/9 showed significantly lower A&E use (30–40%). 10/25 reviews reported significant cost reductions but provided little robust evidence. Effective interventions included discharge management with postdischarge support, MDT care with teams that include condition-specific expertise, specialist nurses and/or pharmacists and self-management as an adjunct to broader interventions. Interventions were most effective when targeting single conditions such as heart failure, and when care was provided in patients’ homes.

Conclusions

Although all outcomes showed some significant reductions, and a number of potentially effective interventions were found, interventions rarely demonstrated unequivocally positive effects. Despite the centrality of integrated care to current policy, questions remain about whether the magnitude of potentially achievable gains is enough to satisfy national targets for reductions in hospital activity.

Trial registration number

CRD42015016458.
Efficacy of intravenous nicorandil for fractional flow reserve assessment: study protocol for a crossover randomised trial
Authors: Nishi Takeshi , Kitahara Hideki , Fujimoto Yoshihide , Nakayama Takashi , Sugimoto Kazumasa , Nagashima Kengo , Hanaoka Hideki , Kobayashi Yoshio
Published: November 2016

Introduction

Nicorandil has vasodilatory effects on both the epicardial coronary arteries and the coronary microvasculature, thereby increasing coronary blood flow. Intravenous administration of nicorandil can be applicable for fractional flow reserve (FFR) measurement as a hyperaemic agent and a possible alternative to adenosine. However, the effectiveness of intravenous nicorandil infusion for FFR measurement is largely unclear.

Methods and analysis

This crossover randomised study is being performed to investigate the efficacy of intravenous administration of nicorandil for FFR measurement. Patients with an intermediate coronary artery stenosis who satisfy the eligibility criteria undergo FFR measurement with a consecutive randomised order of patient-blind infusions of continuous intravenous administration of adenosine and a single bolus intravenous administration of nicorandil. The primary end point of the study is the agreement between the FFR values obtained by the intravenous nicorandil and those obtained by the intravenous adenosine. Recruitment of this trial started in November 2015 and will end in March 2017, or until a total of 50 participants have been recruited.

Ethics and dissemination

The protocol was approved by the Institutional Review Board at Chiba University Hospital. Study findings will be published in peer-reviewed journals.

Trial registration number

UMIN000019309; Pre-results.
Qualitative study of physicians' varied uses of biomedical research in the USA
Authors: Maggio Lauren A , Moorhead Laura L , Willinsky John M
Published: November 2016

Objective

To investigate the nature of physicians' use of research evidence in experimental conditions of open access to inform training and policy.

Design

This qualitative study was a component of a larger mixed-methods initiative that provided 336 physicians with relatively complete access to research literature via PubMed and UpToDate, for 1 year via an online portal, with their usage recorded in web logs. Using a semistructured interview protocol, a subset of 38 physician participants were interviewed about their use of research articles in general and were probed about their reasons for accessing specific articles as identified through their web logs. Transcripts were analysed using a general inductive approach.

Setting

Physician participants were recruited from and registered in the USA.

Participants

38 physicians from 16 US states, engaged in 22 medical specialties, possessing more than 1 year of experience postresidency training participated.

Results

26 participants attested to the value of consulting research literature within the context of the study by making reference to their roles as clinicians, educators, researchers, learners, administrators and advocates. The physicians reported previously encountering what they experienced as a prohibitive paywall barrier to the research literature and other frustrations with the nature of information systems, such as the need for passwords.

Conclusions

The findings, against the backdrop of growing open access to biomedical research, indicate that a minority of physicians, at least initially, is likely to seek out and use research and do so in a variety of common roles. Physicians' use of research in these roles has not traditionally been part of their training or part of the considerations for open access policies. The findings have implications for educational and policy initiatives directed towards increasing the effectiveness of this access to and use of research in improving the quality of healthcare.
Primary cilia are increased in number and demonstrate structural abnormalities in human cancer
Authors: Yasar Binnaz , Linton Kim , Slater Christian , Byers Richard
Published: November 2016

Aims

Primary cilia play an important role in the regulation of cell signalling pathways and are thought to have a role in cancer but have seldom been studied in human cancer samples.

Methods

Primary cilia were visualised by dual immunofluorescence for anti-CROCC (ciliary rootlet coiled-coil) and anti-tubulin in a range of human cancers (including carcinomas of stomach, pancreas, prostate, lung and colon, lobular and ductal breast cancers and follicular lymphoma) and in matched normal tissue (stomach, pancreas, lung, large and small intestines, breast and reactive lymph nodes) samples using a tissue microarray; their frequency, association with proliferation, was measured by Ki-67 staining and their structure was analysed.

Results

Compared with normal tissues, primary cilia frequency was significantly elevated in adenocarcinoma of the lung (2.75% vs 1.85%, p=0.016), adenocarcinoma of the colon (3.80% vs 2.43%, respectively, p=0.017), follicular lymphoma (1.18% vs 0.83%, p=0.003) and pancreatic adenocarcinoma (7.00% vs 5.26%, p=0.002); there was no statistically significant difference compared with normal control tissue for gastric and prostatic adenocarcinomas or for lobular and ductal breast cancers. Additionally, structural abnormalities of primary cilia were identified in cancer tissues, including elongation of the axoneme, multiple basal bodies and branching of the axoneme. Ki-67 scores ranged from 0.7% to 78.4% and showed no statistically significant correlation with primary cilia frequency across all tissues (p=0.1501).

Conclusions

The results show upregulation of primary cilia and the presence of structural defects in a wide range of human cancer tissue samples demonstrating association of dysregulation of primary cilia with human cancer.
No association between elevated homocysteine levels and carotid atherosclerosis in a rural population in China
Authors: Li Yang , Wang Li , Zhang Wei , Fang Yalan , Niu Xiaoyuan
Published: November 2016

Objectives

We wish to determine if homocysteine (Hcy) is an independent risk factor for carotid atherosclerosis in a rural Chinese population.

Methods

2291 individuals (1016 men and 1275 women), aged 64.6±7.4 years, from Lvliang, China participated in this study. Tests performed included carotid artery ultrasound scan and blood analysis, to measure Hcy levels and other blood components.

Results

The mean serum Hcy level was 24.7±18.0 µmol/L. The overall detection rate of carotid atherosclerotic lesions was 76.3% and the detection rate of plaque was 48.6%. Participants were divided into 4 groups based on their Hcy levels, <14.49, 14.49–19.43, 19.44–28.30, and ≥28.30 µmol/L. The relative risk of carotid atherosclerosis for each quartile as compared with the risk for the lowest quartile was estimated as the OR derived from the logistic regression coefficients. After adjusting for age and gender, the OR of carotid atherosclerosis in the third and fourth quartiles of Hcy were 1.219 (95% CI 0.922 to 1.612) and 1.156 (95% CI 0.859 to 1.555; p>0.05), respectively. After controlling for demographic variables (age, gender, current smoker, fasting blood glucose, low-density lipoprotein and systolic blood pressure) the OR of carotid plaque(s) in the third and fourth quartiles were 1.246 (95% CI 0.967 to 1.606) and 1.259 (95% CI 0.963 to 1.646; p>0.05).

Conclusions

The mean value of Hcy among participants in this study was much higher than that previously reported. However, no significant correlation between elevated Hcy and carotid atherosclerosis was found.
Topological indices of rhombus type silicate and oxide networks
Authors: Javaid M. , Rehman Masood Ur , Cao Jinde
Published: November 2016

For a molecular graph, a numeric quantity that characterizes the whole structure of a graph is called a topological index. In the studies of quantitative structure – activity relationship (QSAR) and quantitative structure – property relationship (QSPR), topological indices are utilized to guess the bioactivity of chemical compounds. In this paper, we compute general Randić, first general Zagreb, generalized Zagreb, multiplicative Zagreb, atom-bond connectivity (ABC), and geometric arithmetic (GA) indices for the rhombus silicate and rhombus oxide networks. In addition, we also compute the latest developed topological indices such as the fourth version of ABC (ABC4), the fifth version of GA (GA5), augmented Zagreb, and Sanskruti indices for the foresaid networks. At the end, a comparison between all the indices is included, and the result is shown with the help of a Cartesian coordinate system.
Social cues may advertise habitat quality to refuge-seeking conspecifics
Authors: Elvidge C.K. , Cooke E.L.L. , Cunjak R.A. , Cooke S.J.
Published: November 2016

Individuals travelling through landscapes may use the presence of conspecifics to evaluate habitat quality. Juvenile Atlantic salmon (Salmo salar L., 1758) are usually territorial and exhibit some degree of density-dependent regulation in wild populations. They are also vulnerable to heat stress and may need to locate a thermal refuge to offset metabolic costs above certain temperature thresholds. During July 2010, a heat wave resulted in water temperatures in the Miramichi River system exceeding 30 °C. During this period, salmon parr were observed aggregating in cold-water refugia at densities several orders of magnitude greater than usual. We tested whether groups of wild-caught salmon parr held at high densities (160 parr/m2) would have an attractant effect on free-swimming parr at three sites differing in temperature between 16.5 and 24 °C. Although neither temperature nor site influenced the number of parr that we observed, there were significantly more parr in close proximity (<1 m) to the artificial aggregations than to the controls. These results suggest that social cues from high-density aggregations of conspecifics during extreme temperature events may advertise the location of thermal refugia to others. Understanding how heat-stressed salmon locate refugia may prove valuable to ongoing conservation efforts given the likelihood of increasingly frequent and extreme high-temperature events.
Detectors and experiments
Authors: Hauptman John
Published: November 2016

The talks in the Program and the Conference parallel sessions make clear that high quality pixel vertex chambers are presently well developed and with continuing improvements (M. Caccia,1 X. Sun,2 M. Stanitzki,3 J. Qian4); that there are at least two major tracking chambers that are well studied, a TPC and silicon-strip chambers (H. Qi,[Formula: see text] C. Young,[Formula: see text] A. de Roeck[Formula: see text]); that the energy measurement of photons and electrons is generally very good (H. Yang,[Formula: see text] S. Franchino[Formula: see text]); and, that the last remaining detector that has not yet achieved the high precision required for good [Formula: see text] physics is the hadronic calorimeter for the measurement of jets, most importantly, jets from the decays of [Formula: see text] and [Formula: see text] to quarks (S. Lee,[Formula: see text] M. Cascella,[Formula: see text] A. de Roeck[Formula: see text]). The relationship of the detectors to physics and the overall design of detectors was addressed and questioned (Y. Gao,[Formula: see text] M. Ruan,[Formula: see text] G. Tonelli,[Formula: see text] H. Zhu,[Formula: see text] M. Mangano,[Formula: see text] C. Quigg[Formula: see text]) in addition to precision time measurements in detectors (C. Tully[Formula: see text]).
Stochastic Bifurcations and Noise-Induced Chaos in 3D Neuron Model
Authors: Bashkirtseva Irina , Fedotov Sergei , Ryashko Lev , Slepukhina Evdokia
Published: November 2016

The stochastically forced three-dimensional Hindmarsh–Rose model of neural activity is considered. We study the effect of random disturbances in parametric zones where the deterministic model exhibits mono- and bistable dynamic regimes with period-adding bifurcations of oscillatory modes. It is shown that in both cases the phenomenon of noise-induced bursting is observed. In the monostable zone, where the only attractor of the system is a stable equilibrium, this effect is connected with a stochastic generation of large-amplitude oscillations due to the high excitability of the model. In a parametric zone of coexisting stable equilibria and limit cycles, bursts appear due to noise-induced transitions between the attractors. For a quantitative analysis of the noise-induced bursting and corresponding stochastic bifurcations, an approach based on the stochastic sensitivity function (SSF) technique is applied. Our estimations of the strength of noise that generates such qualitative changes in stochastic dynamics are in a good agreement with the direct numerical simulation. A relationship of the noise-induced generation of bursts with transitions from order to chaos is discussed.
Simple Chaotic Flows with a Curve of Equilibria
Authors: Barati Kosar , Jafari Sajad , Sprott Julien Clinton , Pham Viet-Thanh
Published: November 2016

Using a systematic computer search, four simple chaotic flows with cubic nonlinearities were found that have the unusual feature of having a curve of equilibria. Such systems belong to a newly introduced category of chaotic systems with hidden attractors that are important and potentially problematic in engineering applications.
New Heteroclinic Orbits Coined
Authors: Wang Haijun , Li Chang , Li Xianyi
Published: November 2016

We devote to studying the problem for the existence of homoclinic and heteroclinic orbits of Unified Lorenz-Type System (ULTS). Other than the known results that the ULTS has two homoclinic orbits to [Formula: see text] for [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and two heteroclinic orbits to [Formula: see text] for [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] on its invariant algebraic surface [Formula: see text], formulated in the literature by Yang and Chen [2014], we seize two new heteroclinic orbits of this Unified Lorenz-Type System. Namely, we rigorously prove that this system has another two heteroclinic orbits to [Formula: see text] and [Formula: see text] while no homoclinic orbit when [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text].
Analytical Solution and Soliton-Like Behavior for the (1+1)-Dimensional Quantum System with Generalized Cubic-Quintic Nonlinearity
Authors: Wang Ying , Li Shaohong , Guo Jiyuan , Zhou Qingchun , Zhou Yu , Wen Wen
Published: November 2016

We study the [Formula: see text]-dimensional generalized cubic-quintic nonlinear Schrödinger equation (GCQ–NLSE) with two nonlinear terms that is in cubic-quintic formulation and the general format of polytropic approximation. We find the analytical solution of the GCQ–NLSE through the [Formula: see text]-expansion method without utilizing any integrability condition. We apply the analytical results to the concrete system that supports dark soliton and reach the analytical formula for the sound speed based on the results from the theoretical treatment of GCQ–NLSE. We show that our derived results match pretty well with measured sound velocity values in the off-center regions of the BCS–BEC crossover regime under the same parametric setting, demonstrating the applicability of our theoretical treatment.
Spatiotemporal Dynamics and Hopf Bifurcation in a Delayed Diffusive Intraguild Predation Model with Holling II Functional Response
Authors: Han Renji , Dai Binxiang
Published: November 2016

We propose a kind of delayed diffusive intraguild predation model with Holling II functional response in this paper. By analyzing the eigenvalue spectrum, it is found that the stability or instability of equilibria can be induced by delay. By utilizing the local bifurcation theory of partial functional differential equations, Hopf bifurcation of the proposed system with time delay as bifurcation parameter is investigated. It reveals that the time delay has a destabilizing effect in the intraguild predation model dynamics and a phenomenon of Hopf bifurcation occurs when the delay increases through a certain threshold. Then we give the explicit formulas to determine the direction, stability of Hopf bifurcation by utilizing the normal form method and center manifold reduction for PFDEs. Numerical simulations are performed to illustrate our theoretical results and show that delay and diffusion can induce the system into chaos and even trigger the emergence of different types of spatial patterns, including spiral wave pattern and chaotic wave pattern, which are induced by Hopf instability.
Global Dynamics of Memristor Oscillator
Authors: Chen Hebai
Published: November 2016

In this paper, we investigate the global dynamics of a memristor oscillator [Formula: see text] which comes from [Corinto et al., 2011], where [Formula: see text], and [Formula: see text]. Clearly, the case [Formula: see text] is trivial. So far, all results of this oscillator were given only for the case [Formula: see text], where the set of equilibria may change among a singleton, three points and a singular continuum and at most one limit cycle can arise and no limit cycles arise from the continuum. Compared with the case [Formula: see text], this oscillator displays more complicated dynamics for the case when [Formula: see text]. More clearly, one limit cycle may arise from the continuum and at most three limit cycles appear in the case of three equilibria, where generalized pitchfork bifurcation, saddle-node bifurcation, generalized Hopf bifurcation, double limit cycle bifurcation and homoclinic bifurcation may occur. Finally all global phase portraits are given for [Formula: see text] cases on the Poincaré disc, where a generalized normal sector method is applied. Moreover, our partial analytical results are demonstrated by numerical examples.
Adaptive Control of Fast-Scale Bifurcation in Peak Current Controlled Buck-Boost Inverter via One-Cycle Compensation
Authors: Zhang Hao , Dong Shuai , Guan Weimin , Yi Chuanzhi , He Bo
Published: November 2016

In this paper, one-cycle compensation (OCC) method is proposed to realize adaptive control of fast-scale bifurcation in the peak current controlled buck-boost inverter because the proposed control method can adjust the slope of the integrator’s output voltage automatically through extracting a sinusoidal signal from the absolute value of the reference voltage. In order to reveal their underlying mechanisms of fast-scale bifurcations, a modified averaged model which can capture the sample-and-hold effect is derived in detail to describe the fast-scale dynamics of the buck-boost inverter. Based on the proposed model, a theoretical analysis is performed to identify both the fast-scale period-doubling bifurcation and the fast-scale Hopf one by judging in what way the poles loci move. It has been shown that the OCC method can be used not only to discover the unknown dynamical behaviors (i.e. fast-scale Hopf bifurcation), but also to enlarge the stable region in peak current controlled buck-boost inverter. In addition, the critical bifurcation angles and the parameter behavior boundary are given to verify the effectiveness of the adaptive bifurcation control method. Finally, PSpice circuit experiments are performed to verify the above theoretical and numerical results.
Dynamics of a Class of Nonautonomous Lorenz-Type Systems
Authors: Zhang Xu
Published: November 2016

The dynamical properties of a kind of Lorenz-type systems with time-varying parameters are studied. The time-varying ultimate bounds are estimated, and a simple method is provided to generate strange attractors, including both the strange nonchaotic attractors (SNAs) and chaotic attractors. The approach is: (i) take an autonomous system with an ultimate bound from the Lorenz family; (ii) add at least two time-varying parameters with incommensurate frequencies satisfying certain conditions; (iii) choose the proper initial position and time by numerical simulations. Three interesting examples are given to illustrate this method with computer simulations. The first one is derived from the classical Lorenz model, and generates an SNA. The second one generates an SNA or a Lorenz-like attractor. The third one exhibits the coexistence of two SNAs and a Lorenz-like attractor. The nonautonomous Lorenz-type systems present more realistic models, which provide further understanding and applications of the numerical analysis in weather and climate predication, synchronization, and other fields.
Optoelectronic Composite Logic Gates Controlled by the Logic Operation in a VCSEL with External Optical Injection
Authors: Zhong Dongzhou , Luo Wei , Xu Geliang , Ji Yongqiang
Published: November 2016

Based on the polarization switching mechanism in an optically injected vertical-cavity surface-emitting laser (VCSEL), and relying on the new electro-optic modulation theory, we propose a novel approach to implement optoelectronic logic gates. The two linear-polarization (LP) lights from the output of the laser are considered as two logic outputs. Under the electro-optic modulation, one of the logic outputs is the NOT operation with the other one. With the same logic input signal, we perform various digital signal processing (AND, OR, XNOR, NAND, NOR and XOR) in the optical domain, controlling the logic operations of the applied electric field between the two logic input signals. On this basis, the logic operation of half-adder is further implemented.
Pilgrim dark energy models in fractal universe
Authors: Jawad Abdul , Rani Shamaila , Salako Ines G. , Gulshan Faiza
Published: November 2016

We discuss the cosmological implications of interacting pilgrim dark energy (PDE) models (with Hubble, Granda–Oliveros and generalized ghost cutoffs) with cold dark matter ([Formula: see text]CDM) in fractal cosmology by assuming the flat universe. We observe that the Hubble parameter lies within observational suggested ranges while deceleration parameter represents the accelerated expansion behavior of the universe. The equation of state (EoS) parameter ([Formula: see text]) corresponds to the quintessence region and phantom region for different cases of [Formula: see text]. Further, we can see that [Formula: see text]–[Formula: see text] (where prime indicates the derivative with respect to natural logarithmic of scale factor) plane describes the freezing and thawing regions and also corresponds to [Formula: see text] limit for some cases of [Formula: see text] (PDE parameter). It is also noted that the [Formula: see text]–[Formula: see text] (state-finder parameters) plane corresponds to [Formula: see text] limit and also shows the Chaplygin as well as phantom/quintessence behavior. It is observed that pilgrim dark energy models in fractal cosmology expressed the consistent behavior with recent observational schemes.
Integrability conditions of quasi-Newtonian cosmologies in modified gravity
Authors: Abebe Amare , Dunsby Peter K. S. , Solomons Deon
Published: November 2016

We investigate the integrability conditions of a class of shear-free perfect-fluid cosmological models within the framework of anisotropic fluid sources, applying our results to [Formula: see text] dark energy models. Generalizing earlier general relativistic results for timelike geodesics, we extend the potential and acceleration terms of the quasi-Newtonian formulation of integrable dust cosmological models about a linearized Friedmann–Lemaître–Robertson–Walker background and derive the equations that describe their dynamical evolutions. We show that in general, models with an anisotropic fluid source are not consistent, but because of the particular form the anisotropic stress [Formula: see text] takes in [Formula: see text] gravity, the general integrability conditions in this case are satisfied.
INVESTIGATION OF SURFACE GRADIENT MICROSTRUCTURE OF SHOT PEENED S30432 STEEL BY X-RAY LINE PROFILE ANALYSIS METHOD
Authors: ZHAN K. , FANG W. Q. , ZHAO B. , YAN Y. , FENG Q. , JIANG C. H.
Published: November 2016

S30432 steels were processed by multistep shot peening treatment. The refined microstructures, including domain size, microstrain, domain size distribution and texture were characterized by X-ray diffraction (XRD) line profile analysis method, respectively. The results demonstrate that in the deformed layers, a gradient structure is formed after shot peening. The domain size reaches 25[Formula: see text]nm at the surface, then it decreases as the depth increases, but microstrain (0.0027) is the largest at the surface. The domain size distributions at different depths calculated by Rietveld method are consistent with domain size variation along the depth. There are no strong textures after shot peening treatment. The change of microhardness along the depth is in accordance with the gradient microstructure. It is expected that this work can offer useful information for characterizing the microstructure of shot peened materials.
On model-theoretic tree properties
Authors: Chernikov Artem , Ramsey Nicholas
Published: November 2016

We study model theoretic tree properties ([Formula: see text]) and their associated cardinal invariants ([Formula: see text], respectively). In particular, we obtain a quantitative refinement of Shelah’s theorem ([Formula: see text]) for countable theories, show that [Formula: see text] is always witnessed by a formula in a single variable (partially answering a question of Shelah) and that weak [Formula: see text] is equivalent to [Formula: see text] (answering a question of Kim and Kim). Besides, we give a characterization of [Formula: see text] via a version of independent amalgamation of types and apply this criterion to verify that some examples in the literature are indeed [Formula: see text].
Synthesis and spectroscopic properties of photochromic dithienylethene-functionalized subphthalocyanine conjugate
Authors: Shi Maohu , Chen Jingzhi , Shen Zhen
Published: November 2016

A subphthalocyanine-dithienylethene dyad has been synthesized and characterized by 1H-, [Formula: see text]C-NMR, HR-MS, UV-visible and emission spectroscopy. The results show that photoinduced isomerization of dithienylethene moiety from close-form to opened form can be achieved under visible light using subphthalocyanine as a light-harvesting unit and the fluorescence properties of subphthalocyanine could be modulated by the isomerization state of the dithienylethene moiety.
Synthesis under high hydrostatic pressure — a new method to prepare 5,10,15,20-tetrakis[4-(substituted amino)-2,3,5,6-tetrafluorophenyl]porphyrins
Authors: Gomes Ana T.P.C. , Freire Patrícia C. , Domingos Catarina R.M. , Neves Maria G.P.M.S. , Cavaleiro José A.S. , Almeida Paz Filipe A. , Saraiva Jorge A. , Tomé Augusto C.
Published: November 2016

5,10,15,20-Tetrakis(pentafluorophenyl)porphyrin reacts with primary alkylamines and heterocyclic amines, at 50°C and under high pressure (450 MPa), to produce the [Formula: see text]-substituted tetraamino derivatives in high yields. Under similar conditions, the reaction with the bulky dibutylamine and dipentylamine affords the corresponding mono-substituted dialkylaminoporphyrins in 10% yield. This new protocol arises as a considerable improvement of the methods already known, which usually require high temperatures and are not effective when using secondary amines having long alkyl groups.
On weakly n-absorbing subtractive ideals in semirings
Authors: Chaudhari J. N. , Suryawanshi M. D.
Published: November 2016

Let [Formula: see text] be a commutative semiring with identity [Formula: see text]. In this paper weakly [Formula: see text]-absorbing ideal of [Formula: see text] which is a generalization of weakly prime ideal of [Formula: see text] is introduced and some related results are obtained.
On Eshelby's S-tensor under various magneto-electro-elastic constitutive settings, and its application to multiferroic composites
Authors: Wang Yang , Weng George J.
Published: November 2016

The magneto-electro-elastic Eshelby S-tensor is the key to the study of linear effective properties of magneto-electro-elastic composites. There are eight different ways to write the constitutive relations, and each is associated with a specific kind of boundary condition and Eshelby S-tensor. In this work, we provide a general procedure to convert the magneto-electro-elastic Eshelby S-tensor from one system to another. As an application, we use it to calculate the magnetoelectric coupling coefficients of a piezoelectric–piezomagnetic multiferroic composite under stress-and strain-prescribed boundary conditions. We demonstrate that the calculated results are significantly different. In particular, it is shown that, under an applied stress, the magnetoelectric coupling coefficient [Formula: see text], is much stronger than that under an applied strain, while for [Formula: see text], the values are positive under a prescribed stress but negative under a prescribed strain. The effects of inclusion shape, volume concentration and geometrical exchange, are also examined. For ready applications, the explicit forms of S-tensor, [Formula: see text] and [Formula: see text], of 1-3 fibrous and 2-2 multilayer composites are also provided at the end.
News from the SIGs
Authors: Walker Ellen , Settle Amber , Zilora Steve
Published: November 2016

In this issue of News from the SIGs, we welcome the newly elected chair of SIGCSE, Amber Settle. Amber is the Vincent de Paul Associate Professor of Computer Science at DePaul University. Previous to being elected SIGCSE Chair, she served six years on the SIGCSE Board, including three as Treasurer. Amber discusses some issues currently facing the SIGCSE Board. We also have a report from Steve Zilora, our continuing SIGITE reporter and SIGITE chair, discussing the latest SIGITE/RIIT conference and encouraging more submissions to RIIT.
Sagittal and Vertical Craniofacial Growth Pattern and Timing of Circumpubertal Skeletal Maturation: A Multiple Regression Study
Authors: Perinetti Giuseppe , Rosso Luigi , Riatti Riccardo , Contardo Luca
Published: November 2016

The knowledge of the associations between the timing of skeletal maturation and craniofacial growth is of primary importance when planning a functional treatment for most of the skeletal malocclusions. This cross-sectional study was thus aimed at evaluating whether sagittal and vertical craniofacial growth has an association with the timing of circumpubertal skeletal maturation. A total of 320 subjects (160 females and 160 males) were included in the study (mean age,12.3±1.7years; range, 7.6–16.7 years). These subjects were equally distributed in the circumpubertal cervical vertebral maturation (CVM) stages 2 to 5. Each CVM stage group also had equal number of females and males. Multiple regression models were run for each CVM stage group to assess the significance of the association of cephalometric parameters (ANB, SN/MP, and NSBa angles) with age of attainment of the corresponding CVM stage (in months). Significant associations were seen only for stage 3, where the SN/MP angle was negatively associated with age (βcoefficient, −0.7). These results show that hyperdivergent and hypodivergent subjects may have an anticipated and delayed attainment of the pubertal CVM stage 3, respectively. However, such association remains of little entity and it would become clinically relevant only in extreme cases.