bluuebunny/crossref_metadata_2025 huggingface dataset:
VfrB Is a Key Activator of the Staphylococcus aureus SaeRS Two-Component System
Authors: Krute Christina N. , Rice Kelly C. , Bose Jeffrey L.
Published: December 2016

In previous studies, we identified the fatty acid kinase virulence factor regulator B (VfrB) as a potent regulator of α-hemolysin and other virulence factors in
Staphylococcus aureus
. In this study, we demonstrated that VfrB is a positive activator of the SaeRS two-component regulatory system. Analysis of
vfrB
,
saeR
, and
saeS
mutant strains revealed that VfrB functions in the same pathway as SaeRS. At the transcriptional level, the promoter activities of SaeRS class I (
coa
) and class II (
hla
) target genes were downregulated during the exponential growth phase in the
vfrB
mutant, compared to the wild-type strain. In addition,
saePQRS
expression was decreased in the
vfrB
mutant strain, demonstrating a need for this protein in the autoregulation of SaeRS. The requirement for VfrB-mediated activation was circumvented when SaeS was constitutively active due to an SaeS (L18P) substitution. Furthermore, activation of SaeS via human neutrophil peptide 1 (HNP-1) overcame the dependence on VfrB for transcription from class I Sae promoters. Consistent with the role of VfrB in fatty acid metabolism,
hla
expression was decreased in the
vfrB
mutant with the addition of exogenous myristic acid. Lastly, we determined that aspartic acid residues D38 and D40, which are predicted to be key to VfrB enzymatic activity, were required for VfrB-mediated α-hemolysin production. Collectively, this study implicates VfrB as a novel accessory protein needed for the activation of SaeRS in
S. aureus
.

IMPORTANCE
The SaeRS two-component system is a key regulator of virulence determinant production in
Staphylococcus aureus
. Although the regulon of this two-component system is well characterized, the activation mechanisms, including the specific signaling molecules, remain elusive. Elucidating the complex regulatory circuit of SaeRS regulation is important for understanding how the system contributes to disease causation by this pathogen. To this end, we have identified the fatty acid kinase VfrB as a positive regulatory modulator of SaeRS-mediated transcription of virulence factors in
S. aureus
. In addition to describing a new regulatory aspect of SaeRS, this study establishes a link between fatty acid kinase activity and virulence factor regulation.
Levels of Antibody against Glycopeptidolipid Core as a Marker for Monitoring Treatment Response in Mycobacterium avium Complex Pulmonary Disease: a Prospective Cohort Study
Authors: Kitada Seigo , Maekura Ryoji , Yoshimura Kenji , Miki Keisuke , Miki Mari , Oshitani Yohei , Nishida Kohei , Sawa Nobuhiko , Mori Masahide , Kobayashi Kazuo
Published: December 2016

The diagnosis of
Mycobacterium avium
complex pulmonary disease (MAC-PD) is sometimes complicated and time-consuming. A serodiagnostic kit that measures the serum levels of IgA antibodies against the glycopeptidolipid (GPL) core is commercially available and has good diagnostic accuracy for MAC-PD. However, the significance of measurement of GPL core IgA antibody levels in monitoring for chemotherapy response in patients with MAC-PD was not well investigated. Thirty-four treatment naive MAC-PD patients who were started on multidrug chemotherapy were enrolled. Their antibody levels were prospectively measured at regular intervals. The relationships between their antibody levels and the therapeutic outcomes were examined. The patients were classified into three groups (conversion, recurrence, and nonconversion) based on the bacteriological outcomes after chemotherapy. There were no significant differences in the antibody levels before treatment between the culture conversion (
n
= 19), recurrence (
n
= 7), and nonconversion (
n
= 8) groups (
P
= 0.9881). The levels decreased significantly after the chemotherapy (
P
< 0.0001). Recurrence and/or worsening of chest radiography findings were observed in cases whose antibody levels subsequently increased after cessation of the chemotherapy. No significant difference in the percent decrease in antibody levels by the chemotherapy was observed between the culture conversion and recurrence groups (
P
= 0.9338). The initial antibody levels are not a predictor of therapeutic outcomes, and also the percent decrease in antibody levels is not a sufficient indicator of the cessation of chemotherapy. However, serial measurements of antibody levels may allow objective monitoring of disease activity in individual MAC-PD patients.
Severe Symptomatic Primary Human Cytomegalovirus Infection despite Effective Innate and Adaptive Immune Responses
Authors: Riou Raphaëlle , Bressollette-Bodin Céline , Boutoille David , Gagne Katia , Rodallec Audrey , Lefebvre Maeva , Raffi François , Senitzer David , Imbert-Marcille Berthe-Marie , Retière Christelle
Published: December 2016

Primary human cytomegalovirus (HCMV) infection usually goes unnoticed, causing mild or no symptoms in immunocompetent individuals. However, some rare severe clinical cases have been reported without investigation of host immune responses or viral virulence. In the present study, we investigate for the first time phenotypic and functional features, together with gene expression profiles in immunocompetent adults experiencing a severe primary HCMV infection. Twenty primary HCMV-infected patients (PHIP) were enrolled, as well as 26 HCMV-seronegative and 39 HCMV-seropositive healthy controls. PHIP had extensive lymphocytosis marked by massive expansion of natural killer (NK) and T cell compartments. Interestingly, PHIP mounted efficient innate and adaptive immune responses with a deep HCMV imprint, revealed mainly by the expansion of NKG2C
+
NK cells, CD16
+
Vδ2(−) γδ T cells, and conventional HCMV-specific CD8
+
T cells. The main effector lymphocytes were activated and displayed an early immune phenotype that developed toward a more mature differentiated status. We suggest that both massive lymphocytosis and excessive lymphocyte activation could contribute to massive cytokine production, known to mediate tissue damage observed in PHIP. Taken together, these findings bring new insights into the comprehensive understanding of immune mechanisms involved during primary HCMV infection in immunocompetent individuals.

IMPORTANCE
HCMV-specific immune responses have been extensively documented in immunocompromised patients and during
in utero
acquisition. While it usually goes unnoticed, some rare severe clinical cases of primary HCMV infection have been reported in immunocompetent patients. However, host immune responses or HCMV virulence in these patients has not so far been investigated. In the present study, we show massive expansion of NK and T cell compartments during the symptomatic stage of acute HCMV infection. The patients mounted efficient innate and adaptive immune responses with a deep HCMV imprint. The massive lymphocytosis could be the result of nonadapted or uncontrolled immune responses limiting the effectiveness of the specific responses mounted. Both massive lymphocytosis and excessive lymphocyte activation could contribute to massive cytokine production, known to mediate tissue damage. Furthermore, we cannot exclude a delayed immune response caused by immune escape established by HCMV strains.
Screening for Novel Small-Molecule Inhibitors Targeting the Assembly of Influenza Virus Polymerase Complex by a Bimolecular Luminescence Complementation-Based Reporter System
Authors: Li Chunfeng , Wang Zining , Cao Yang , Wang Lulan , Ji Jingyun , Chen Zhigao , Deng Tao , Jiang Taijiao , Cheng Genhong , Qin F. Xiao-Feng
Published: December 2016

Influenza virus RNA-dependent RNA polymerase consists of three viral protein subunits: PA, PB1, and PB2. Protein-protein interactions (PPIs) of these subunits play pivotal roles in assembling the functional polymerase complex, which is essential for the replication and transcription of influenza virus RNA. Here we developed a highly specific and robust bimolecular luminescence complementation (BiLC) reporter system to facilitate the investigation of influenza virus polymerase complex formation. Furthermore, by combining computational modeling and the BiLC reporter assay, we identified several novel small-molecule compounds that selectively inhibited PB1-PB2 interaction. Function of one such lead compound was confirmed by its activity in suppressing influenza virus replication. In addition, our studies also revealed that PA plays a critical role in enhancing interactions between PB1 and PB2, which could be important in targeting sites for anti-influenza intervention. Collectively, these findings not only aid the development of novel inhibitors targeting the formation of influenza virus polymerase complex but also present a new tool to investigate the exquisite mechanism of PPIs.

IMPORTANCE
Formation of the functional influenza virus polymerase involves complex protein-protein interactions (PPIs) of PA, PB1, and PB2 subunits. In this work, we developed a novel BiLC assay system which is sensitive and specific to quantify both strong and weak PPIs between influenza virus polymerase subunits. More importantly, by combining
in silico
modeling and our BiLC assay, we identified a small molecule that can suppress influenza virus replication by disrupting the polymerase assembly. Thus, we developed an innovative method to investigate PPIs of multisubunit complexes effectively and to identify new molecules inhibiting influenza virus polymerase assembly.
Nine-year study of US high school soccer injuries: data from a national sports injury surveillance programme
Authors: Khodaee Morteza , Currie Dustin W , Asif Irfan M , Comstock R Dawn
Published: December 2016

Background

Research on high school soccer injury epidemiology is sparse.

Aim

To describe high school soccer injury rates, trends and patterns by type of athlete exposure (AE), position and sex.

Methods

This descriptive epidemiological study used data from a large national high school sports injury surveillance programme to describe rates and patterns of soccer-related injuries including concussion sustained from 2005/2006 to 2013/2014. Injury rates are calculated per 1000 AEs.

Results

Overall, 6154 soccer injuries occurred during 2 985 991 AEs; injury rate=2.06 per 1000 AEs. Injury rates were higher during competition (4.42) than practice (1.05; rate ratio (RR)=4.19; 95% CI 3.98 to 4.41), and in girls (2.33) than boys (1.83; RR=1.27, 95% CI 1.21 to 1.34). Boys' non-concussion injury rates decreased significantly (p=0.001) during the study period while reported concussion rates increased significantly (p=0.002). Girls' non-concussion rates were relatively stable and reported concussion rates increased significantly (p=0.004). Player–player contact was the injury mechanism that led to the most competition injuries (injury proportion ratio (IPR)=2.87; 95% CI 2.57 to 3.21), while non-contact injuries were the most common mechanisms among practice injuries (IPR=2.10; 95% CI 1.86 to 2.38). Recovery from concussion was >7 days in a third of the cases. Injury patterns were similar between sexes with respect to position played and location on the field at the time of injury.

Conclusions

High school soccer injury rates vary by sex and type of exposure, while injury patterns are more similar across sexes. Reported concussion rates increased significantly over the study period in male and female athletes.
Factors associated with influenza vaccination coverage among the elderly in South Korea: the Fourth Korean National Health and Nutrition Examination Survey (KNHANES IV)
Authors: Kwon David Soonil , Kim Kyuwoong , Park Sang Min
Published: December 2016

Objective

The annual outbreak of influenza is one of the major causes of morbidity and mortality among the elderly population around the world. While there is an annual vaccine available to prevent or reduce the incidence of disease, not all older people in Korea choose to be vaccinated. There have been few previous studies to examine the factors influencing influenza vaccination in Korea. Thus, this study identifies nationwide factors that affect influenza vaccination rates in elderly Koreans.

Methods

We obtained data from the Fourth Korean National Health and Nutrition Examination Survey 2007–2009 (KNHANES IV), a nationwide health survey in Korea. To assess influenza vaccination status, we analysed answers to a single question from the survey. From the respondents, we selected 3567 elderly population aged 65 years or older, to analyse the effects of variables including sociodemographic, health behavioural risk, health status and psychological factors on vaccination coverage. We identified factors that affect vaccination status using a multiple logistic regression analysis.

Results

The rate of influenza vaccination in this elderly population was 75.8%. Overall, the most significant determinants for choosing influenza vaccination were a recent history of health screening (adjusted OR (aOR) 2.26, 95% CI 1.92 to 2.66) and smoking (aOR 0.78, 95% CI 0.62 to 0.98). Other contributing factors were age, household income, marital status, alcohol consumption, physical activity level, self-reported health status and a limitation in daily activities. In contrast, psychological factors, including self-perceived quality of life, stress and depressive mood, did not show close association with vaccination coverage.

Conclusions

To boost influenza vaccination rates in the elderly, an influenza campaign should focus on under-represented groups, especially smokers. Additionally, promoting routine health screening for the elderly may be an efficient way to help achieve higher vaccination rates. Our results highlight the need for a new strategy for the vaccination campaign.
Improving capacity and consent to treatment recording in psychiatric inpatient wards: A multi-centre quality improvement project
Authors: Li Ching , Stellman Judith , Patel Nitisha , Dalton Florence
Published: December 2016

Assessment of mental capacity provides an ethical and legal framework for care which values patients' autonomy whilst recognising the instances where it is appropriate to act in patients' best interests.

Existing medical literature indicates that mental capacity is poorly documented in psychiatric inpatient settings. The aim of the project was to examine the frequency of capacity and consent to treatment documentation with a view to creating changes in practice by raising awareness about the importance of assessing and documenting mental capacity.

A multi-centre quality improvement project was conducted in September 2014 across all general adult psychiatric inpatient wards in the North Central London Training Scheme. The frequency of documentation of capacity and consent to treatment for all adult psychiatric inpatient wards across North Central London was measured.

Electronic patient notes were audited retrospectively to ascertain whether capacity and consent to treatment on admission, and within the preceding seven days of data collection, was recorded. Data was collected across three successive time points during a 12 month period following the implementation of changes. A total of 232 patients were included in the baseline measurements. The results highlighted a deficiency in the recording of capacity and consent to treatment for adult psychiatric inpatients. The results showed that, of the patients audited, 49.8% had their capacity and consent to treatment assessed on admission, 61.9% had a capacity assessment in the previous 7 days and 60.5% had consent recorded in the previous 7 days. These findings were presented at local hospital teaching sessions at each of the audited sites. These sessions also gave teaching on mental capacity. Audit cycle 1 was conducted 6 months later, this included 213 patients and showed a 30% improvement in the frequency of documentation across all measures. The results showed that 77% of patients audited had their capacity and consent assessed on admission to the ward, 87.3% had a capacity assessment in the previous 7 days and 85.5% had consent recorded in the previous 7 days. After feedback from the teaching sessions, a clerking proforma was produced that had a prompt to assess to capacity. Audit cycle 2 was conducted 12 months after the initial baseline measurements, had a sample size of 229 patients and a sustained improvement in documentation of 26% from baseline was demonstrated across all measures.

This project demonstrated that capacity and consent to treatment was not routinely recorded but that the frequency of recording improved through the use of teaching sessions on mental capacity and the introduction of admission clerking proformas with capacity prompts.
Using the Safer Clinical Systems approach and Model for Improvement methodology to decrease Venous Thrombo-Embolism in Elective Surgical Patients
Authors: Humphries Angela , Peden Carol , Jordan Lesley , Crowe Josephine , Peden Carol
Published: December 2016

A significant incidence of post-procedural deep vein thrombosis (DVT) and pulmonary embolus (PE) was identified in patients undergoing surgery at our hospital. Investigation showed an unreliable peri-operative process leading to patients receiving incorrect or missed venous thromboembolism (VTE) prophylaxis. The Trust had previously participated in a project funded by the Health Foundation using the “Safer Clinical Systems” methodology to assess, diagnose, appraise options, and implement interventions to improve a high risk medication pathway. We applied the methodology from that study to this cohort of patients demonstrating that the same approach could be applied in a different context.

Interventions were linked to the greatest hazards and risks identified during the diagnostic phase. This showed that many surgical elective patients had no VTE risk assessment completed pre-operatively, leading to missed or delayed doses of VTE prophylaxis post-operatively. Collaborative work with stakeholders led to the development of a new process to ensure completion of the VTE risk assessment prior to surgery, which was implemented using the Model for Improvement methodology. The process was supported by the inclusion of a VTE check in the Sign Out element of the WHO Surgical Safety Checklist at the end of surgery, which also ensured that appropriate prophylaxis was prescribed. A standardised operation note including the post-operative VTE plan will be implemented in the near future. At the end of the project VTE risk assessments were completed for 100% of elective surgical patients on admission, compared with 40% in the baseline data.

Baseline data also revealed that processes for chemical and mechanical prophylaxis were not reliable. Hospital wide interventions included standardisation of mechanical prophylaxis devices and anti-thromboembolic stockings (resulting in a cost saving of £52,000), and a Trust wide awareness and education programme. The education included increased emphasis on use of mechanical prophylaxis when chemical prophylaxis was contraindicated. VTE guidelines were also included in the existing junior Doctor guideline App. and a “CLOTS” anticoagulation webpage was developed and published on the hospital intranet.

The improvement in VTE processes resulted in an 80% reduction in hospital associated thrombosis following surgery from 0.2% in January 2014 to 0.04% in December 2015 and a reduction in the number of all hospital associated VTE from a baseline median of 9 per month as of January 2014 to a median of 1 per month by December 2015.
From Veneziano to Riemann: A string theory statement of the Riemann hypothesis
Authors: He Yang-Hui , Jejjala Vishnu , Minic Djordje
Published: December 2016

We discuss a precise relation between the Veneziano amplitude of string theory, rewritten in terms of ratios of the Riemann zeta function, and two elementary criteria for the Riemann hypothesis formulated in terms of integrals of the logarithm and the argument of the zeta function. We also discuss how the integral criterion based on the argument of the Riemann zeta function relates to the Li criterion for the Riemann hypothesis. We provide a new generalization of this integral criterion. Finally, we comment on the physical interpretation of our recasting of the Riemann hypothesis in terms of the Veneziano amplitude.
A Locust Phase Change Model with Multiple Switching States and Random Perturbation
Authors: Xiang Changcheng , Tang Sanyi , Cheke Robert A. , Qin Wenjie
Published: December 2016

Insects such as locusts and some moths can transform from a solitarious phase when they remain in loose populations and a gregarious phase, when they may swarm. Therefore, the key to effective management of outbreaks of species such as the desert locust Schistocercagregaria is early detection of when they are in the threshold state between the two phases, followed by timely control of their hopper stages before they fledge because the control of flying adult swarms is costly and often ineffective. Definitions of gregarization thresholds should assist preventive control measures and avoid treatment of areas that might not lead to gregarization. In order to better understand the effects of the threshold density which represents the gregarization threshold on the outbreak of a locust population, we developed a model of a discrete switching system. The proposed model allows us to address: (1) How frequently switching occurs from solitarious to gregarious phases and vice versa; (2) When do stable switching transients occur, the existence of which indicate that solutions with larger amplitudes can switch to a stable attractor with a value less than the switching threshold density?; and (3) How does random perturbation influence the switching pattern? Our results show that both subsystems have refuge equilibrium points, outbreak equilibrium points and bistable equilibria. Further, the outbreak equilibrium points and bistable equilibria can coexist for a wide range of parameters and can switch from one to another. This type of switching is sensitive to the intrinsic growth rate and the initial values of the locust population, and may result in locust population outbreaks and phase switching once a small perturbation occurs. Moreover, the simulation results indicate that the switching transient patterns become identical after some generations, suggesting that the evolving process of the perturbation system is not related to the initial value after some fixed number of generations for the same stochastic processes. However, the switching frequency and outbreak patterns can be significantly affected by the intensity of noise and the intrinsic growth rate of the locust population.
The DPSK Signal Noncoherent Demodulation Receiver Based on the Duffing Oscillators Array
Authors: Fu Yongqing , Li Yanan , Zhang Lin , Li Xingyuan
Published: December 2016

Chaotic communication requires the knowledge of corresponding phase relationship between the primary phase of Duffing oscillator’s internal driving force and the primary phase of the undetected signal. Currently, there is no method of noncoherent demodulation for DPSK (Differential Phase Shift Keying) signal and mobile communication signal by Duffing oscillator. To solve this problem, this study presents a noncoherent demodulation method based on the Duffing oscillators array and Duffing oscillator optimization. We first present the model of Duffing oscillator and its sensitivity to undetected signal primary phase. Then the zone partition is proposed to identify the Duffing oscillator’s phase trajectory, and subsequently, the mathematical model and implementation method of the Duffing oscillators array are outlined. Thirdly, the Duffing oscillator optimization and its adaptive strobe technique are proposed, also their application to DPSK signal noncoherent demodulation are discussed. Finally, the design of new concept DPSK chaotic digital receiver based on the Duffing oscillators array is presented, together with its simulation results obtained by using SystemView simulation platform. The simulation results suggest that the new concept receiver based on the Duffing oscillator optimization of Duffing oscillators array owns better SNR (signal-to-noise ratio) threshold property than typical existing receivers (chaotic or nonchaotic) in the AWGN (additive white Gaussian noise) channel and multipath Rayleigh fading channel. In addition, the new concept receiver may detect mobile communication signal.
Analysis of the Dynamics of Piecewise Linear Memristors
Authors: Jiang Fangfang , Ji Zhicheng , Wang Qing-Guo , Sun Jitao
Published: December 2016

In this paper, we consider a class of flux controlled memristive circuits with a piecewise linear memristor (i.e. the characteristic curve of the memristor is given by a piecewise linear function). The mathematical model is described by a discontinuous planar piecewise smooth differential system, which is defined on three zones separated by two parallel straight lines [Formula: see text] (called as discontinuity lines in discontinuous differential systems). We first investigate the stability of equilibrium points and the existence and uniqueness of a crossing limit cycle for the memristor-based circuit under self-excited oscillation. We then analyze the existence of periodic orbits of forced nonlinear oscillation for the memristive circuit with an external exciting source. Finally, we give numerical simulations to show good matches between our theoretical and simulation results.
Numerical Analysis and Improved Algorithms for Lyapunov-Exponent Calculation of Discrete-Time Chaotic Systems
Authors: He Jianbin , Yu Simin , Cai Jianping
Published: December 2016

Lyapunov exponent is an important index for describing chaotic systems behavior, and the largest Lyapunov exponent can be used to determine whether a system is chaotic or not. For discrete-time dynamical systems, the Lyapunov exponents are calculated by an eigenvalue method. In theory, according to eigenvalue method, the more accurate calculations of Lyapunov exponent can be obtained with the increment of iterations, and the limits also exist. However, due to the finite precision of computer and other reasons, the results will be numeric overflow, unrecognized, or inaccurate, which can be stated as follows: (1) The iterations cannot be too large, otherwise, the simulation result will appear as an error message of NaN or Inf; (2) If the error message of NaN or Inf does not appear, then with the increment of iterations, all Lyapunov exponents will get close to the largest Lyapunov exponent, which leads to inaccurate calculation results; (3) From the viewpoint of numerical calculation, obviously, if the iterations are too small, then the results are also inaccurate. Based on the analysis of Lyapunov-exponent calculation in discrete-time systems, this paper investigates two improved algorithms via QR orthogonal decomposition and SVD orthogonal decomposition approaches so as to solve the above-mentioned problems. Finally, some examples are given to illustrate the feasibility and effectiveness of the improved algorithms.
Constructing a Chaotic System with an Infinite Number of Equilibrium Points
Authors: Pham Viet-Thanh , Jafari Sajad , Kapitaniak Tomasz
Published: December 2016

The chaotic systems with hidden attractors, such as chaotic systems with a stable equilibrium, chaotic systems with infinite equilibria or chaotic systems with no equilibrium have been investigated recently. However, the relationships between them still need to be discovered. This work explains how to transform a system with one stable equilibrium into a new system with an infinite number of equilibrium points by using a memristive device. Furthermore, some other new systems with infinite equilibria are also constructed to illustrate the introduced methodology.
A PRELIMINARY STUDY ON THE FRACTAL PHENOMENON: “DISCONNECTED+ DISCONNECTED=CONNECTED”
Authors: WANG DA , LIU SHUTANG , ZHAO YANG
Published: December 2016

The well-known Parrondo’s paradox: “losing+losing=winning” [G. P. Harmer and D. Abbott, Parrondo’s paradox, Stat. Sci. 14 (2009) 206–213.] indicated that two games with negative gains can generate a new game with positive gain. By extending the Parrondo’s philosophy into chaos research, it was shown that the periodic alteration of two chaotic dynamics results in an ordered dynamics, that is the phenomenon: “chaos+chaos=order” [J. Almeida, D. Peralta-Salas and M. Romera, Can two chaotic systems give rise to order, Physica D 200 124–132 (2005)]. This paper further extends these researches into fractal research by proposing that two disconnected Julia sets can originate a new connected Julia set via alternating order. This new parrondian paradoxical phenomenon can be stated in the Parrondo’s terms as “disconnected+disconnected=connected”.
Selected Properties of the Dynamic Model of the Piston-Crankshaft Assembly in Stirling Engine Combined with the Thermodynamic Submodel
Authors: Chmielewski Adrian , Gumiński Robert , M̧czak Jȩdrzej
Published: December 2016

This work presents a dynamic model of the piston-crankshaft assembly of the Stirling engine with three degrees of freedom combined with the isothermal thermodynamic submodel. The model allowed for consideration of the working gas pressure from the thermodynamic submodel, whose working space was divided into partial volume units and subjected to analysis. Performing the analysis of the physical model and adopting the data from the real object, with the assumption of the static mass reduction, enabled developing of a simulation model of the piston-crankshaft assembly. Subsequently, the model was extended by the part describing pressure changes in the cylinder, theoretical work, theoretical power of the working gas with the assumption of the isothermal heat exchange in the compression and expansion spaces. On the basis of the motion equations shown in the work, the influence of the model’s chosen parameters on the operation of the integrated simulation model was presented and analyzed. The results of the conducted simulations were also additionally derived from an analysis of the displacement, velocity, and piston acceleration curves, as well as the curves of displacement, velocity, and crankshaft angular acceleration. The presented results convey the information about the dynamic operation of the simulated real object working at the preset thermodynamic parameters of the working gas.
FRACTIONAL MODELING OF HYPERBOLIC BIOHEAT TRANSFER EQUATION DURING THERMAL THERAPY
Authors: KUMAR P. , RAI K. N.
Published: December 2016

In this paper, we have developed a fractional hyperbolic bioheat transfer (FHBHT) model by applying fractional Taylor series formula to the single-phase-lag constitutive relation. A new hybrid numerical scheme that combines the multi-resolution and multi-scale computational property of Legendre wavelets based on fractional operational matrix has been used to find the numerical solution of the present problem. This study demonstrates that FHBHT model can provide a unified approach for analyzing heat transfer within living biological tissues, as standard hyperbolic bioheat transfer (SHBHT) and Pennes models are particular cases of FHBHT model. The effect of phase lag time and order of fractional derivative on temperature distribution within living biological tissues for both SHBHT and FHBHT models have been studied and shown graphically. It has been observed that thermal signal propagates more easily with larger values of order of fractional derivative within living biological tissues. The time interval for achieving temperature range of thermal treatment for different models have been studied and compared. It is least for Pennes model, highest for FHBHT model and in between them for SHBHT model. The whole analysis is presented in dimensionless form.
Combined Hybrid Finite Element Method Applied in Elastic Thermal Stress Problem
Authors: Zhang Ling , Nie Yufeng , Yuan Zhanbin , Guo Yang , Wang Huiling
Published: December 2016

In view of combinative stability, combinative variational principle based on domain decomposition for elastic thermal stress problem is constructed with the merits of avoiding Lax–Babuska–Brezzi (LBB) conditions. Compared with the principle of elasticity problem, new load items from thermal are involved. In addition, combined hybrid finite element is proposed to discretize the new principle and to formulate element stiffness matrix. Energy compatibility is introduced not only to simplify the variational principle and the corresponding element stiffness matrix but also to reduce the error of finite element solutions. On cuboid element, the energy compatible stress mode is given explicitly. The numerical results indicate that combined hybrid element with eight nodes can give almost the same computing accuracy of displacement and better computing accuracy of stress compared with cuboid element with 20 nodes, is not sensitive to mesh distortion and can circumvent Poisson-locking phenomenon.
EXAMINING ADAPTATION STRATEGIES OF SUB-SAHARAN AFRICAN IMMIGRANT ENTREPRENEURS IN CHINA: THE CASE OF GUANGDONG
Authors: ADO ABDOULKADRE , CHRYSOSTOME ELIE , SU ZHAN
Published: December 2016

This paper examines how sub-Saharan Africans do business in China, particularly in the province of Guangdong. Through a qualitative approach, the paper analyzes data obtained from twenty interviews with sub-Saharan Africans. It’s a descriptive study that explores the strategies, tactics and attitudes adopted by those sub-Saharan Africans to cope with a particularly difficult Chinese business environment. Using the concepts of foreignness and adaptation, the study identified four categories of immigrant entrepreneurs: the assimilators, the conservatives, the adventurers and the cautious. Concomitantly, this research identified factors and skills that contributed significantly to immigrants’ success in China. The paper also underlines challenges sub-Saharan Africans still face in China and the unconventional tactics they use. The study represents an insightful exploration of an increasingly important subject but still under-studied. It calls for a thorough research toward the understanding of African businesses in China.
MANAGING INTERPERSONAL CONFLICT BETWEEN EXPATRIATES AND THAI MANAGERS THROUGH INTERCULTURAL COMMUNICATION: THE MODERATING EFFECT OF EXPATRIATES’ CULTURE OF ORIGIN
Authors: DARAWONG C. , IGEL B.
Published: December 2016

Intercultural communication has been considered as an effective tool in performing international business in overseas subsidiaries. In this paper, we investigate the impact of intercultural communication on interpersonal conflict between expatriates and Thai managers during the new product development process, and how expatriates’ culture of origin moderates this impact. Data were collected through a questionnaire survey from local managers who regularly communicate with expatriate managers working in Thailand. The results show that intercultural communication reduces relationship conflict and increases task conflict. Furthermore, the negative impact of intercultural communication on relationship conflicts between Asian expatriates and Thai managers is stronger than between Western expatriates and Thai managers. The research results contribute to the existing theories by extending inter-functional communication and conflict to an intercultural context. Also, this research enhances understanding on how the impact of intercultural communication on conflict is moderated by expatriates’ culture of origin, namely Asian and Western. Managerial implications for MNC subsidiaries and future research are also discussed.
Crossed products and minimal dynamical systems
Authors: Lin Huaxin
Published: December 2016

Let [Formula: see text] be an infinite compact metric space with finite covering dimension and let [Formula: see text] be two minimal homeomorphisms. We prove that the crossed product [Formula: see text]-algebras [Formula: see text] and [Formula: see text] are isomorphic if and only if they have isomorphic Elliott invariant. In a more general setting, we show that if [Formula: see text] is an infinite compact metric space and if [Formula: see text] is a minimal homeomorphism such that [Formula: see text] has mean dimension zero, then the tensor product of the crossed product with a UHF-algebra of infinite type has generalized tracial rank at most one. This implies that the crossed product is in a classifiable class of amenable simple [Formula: see text]-algebras.
Risks, Uncertainty and Climate Confusion in the Murray–Darling Basin Reforms
Authors: Alexandra Jason
Published: December 2016

Risks and uncertainties arising from climate change are increasingly recognized as significant challenges for water governance. To support adaptive approaches, critical examinations of water policy practices and rationalities are needed. This paper focuses on the treatment of climate change in Australia’s Murray–Darling Basin (MDB) reforms over the past decade. While the MDB faces potentially significant drying trends due to climate change no reductions in future water availability due to climate change were formalized in the 2012 Basin Plan — a regulatory instrument agreed to by Australia’s National Parliament. The background, key dimensions and possible reasons for this decision are examined. Possible reasons for not formally reducing water deemed available in the future include the complexity and uncertainty of climate science, the cultural construction of “climate normal” based on long-term averages, and institutional settings that reinforce dominant “hydro-logical” approaches and rationalities. Minimizing the political, legal and financial consequences of attributing reductions in water allocations to climate change are also potential reasons. The case of the MDB, as outlined in this paper, demonstrates some of the ways climate change is causing systemic challenges for adaptive water governance, and that innovative approaches need to be embraced, including better processes for institutionalizing science/policy integration.
A family of positivity preserving schemes for numerical solution of Black–Scholes equation
Authors: Khalsaraei M. Mehdizadeh , Jahandizi R. Shokri
Published: December 2016

When one solves the Black–Scholes partial differential equation, it is of great important that numerical scheme to be free of spurious oscillations and satisfy the positivity requirement. With positivity, we mean, the component non-negativity of the initial vector, is preserved in time for the exact solution. Numerically, such property for fully implicit scheme is not always satisfied by approximated solutions and they generate spurious oscillations in the presence of discontinuous payoff. In this paper, by using the nonstandard discretization strategy, we propose a new scheme that is free of spurious oscillations and satisfies the positivity requirement.
Myelo-erythroid commitment after burn injury is under β-adrenergic control via MafB regulation
Authors: Hasan Shirin , Johnson Nicholas B. , Mosier Michael J. , Shankar Ravi , Conrad Peggie , Szilagyi Andrea , Gamelli Richard L. , Muthumalaiappan Kuzhali
Published: December 2016

Severely injured burn patients receive multiple blood transfusions for anemia of critical illness despite the adverse consequences. One limiting factor to consider alternate treatment strategies is the lack of a reliable test platform to study molecular mechanisms of impaired erythropoiesis. This study illustrates how conditions resulting in a high catecholamine microenvironment such as burns can instigate myelo-erythroid reprioritization influenced by β-adrenergic stimulation leading to anemia. In a mouse model of scald burn injury, we observed, along with a threefold increase in bone marrow LSK cells (linneg Sca1+cKit+), that the myeloid shift is accompanied with a significant reduction in megakaryocyte erythrocyte progenitors (MEPs). β-Blocker administration (propranolol) for 6 days after burn, not only reduced the number of LSKs and MafB+ cells in multipotent progenitors, but also influenced myelo-erythroid bifurcation by increasing the MEPs and reducing the granulocyte monocyte progenitors in the bone marrow of burn mice. Furthermore, similar results were observed in burn patients’ peripheral blood mononuclear cell-derived ex vivo culture system, demonstrating that commitment stage of erythropoiesis is impaired in burn patients and intervention with propranolol (nonselective β1,2-adrenergic blocker) increases MEPs. Also, MafB+ cells that were significantly increased following standard burn care could be mitigated when propranolol was administered to burn patients, establishing the mechanistic regulation of erythroid commitment by myeloid regulatory transcription factor MafB. Overall, results demonstrate that β-adrenergic blockers following burn injury can redirect the hematopoietic commitment toward erythroid lineage by lowering MafB expression in multipotent progenitors and be of potential therapeutic value to increase erythropoietin responsiveness in burn patients.
Case Studies in Physiology: Maximal oxygen consumption and performance in a centenarian cyclist
Authors: Billat Véronique , Dhonneur Gilles , Mille-Hamard Laurence , Le Moyec Laurence , Momken Iman , Launay Thierry , Koralsztein Jean Pierre , Besse Sophie
Published: December 2016

The purpose of this study was to examine the physiological characteristics of an elite centenarian cyclist who, at 101 yr old, established the 1-h cycling record for individuals ≥100 yr old (24.25 km) and to determine the physiological factors associated with his performance improvement 2 yr later at 103 yr old (26.92 km; +11%). Before each record, he performed an incremental test on a cycling ergometer. For 2 yr, he trained 5,000 km/yr with a polarized training that involved cycling 80% of mileage at “light” rate of perceived exertion (RPE) ≤12 and 20% at “hard” RPE ≥15 at a cadence between 50 and 70 rpm. His body weight and lean body mass did not change, while his maximal oxygen consumption (V̇o2max) increased (31–35 ml·kg−1·min−1; +13%). Peak power output increased from 90 to 125 W (+39%), mainly because of increasing the maximal pedaling frequency (69–90 rpm; +30%). Maximal heart rate did not change (134–137 beats/min) in contrast to the maximal ventilation (57–70 l/min, +23%), increasing with both the respiratory frequency (38–41 cycles/min; +8%) and the tidal volume (1.5–1.7 liters; +13%). Respiratory exchange ratio increased (1.03–1.14) to the same extent as tolerance to V̇co2. In conclusion, it is possible to increase performance and V̇o2max with polarized training focusing on a high pedaling cadence even after turning 100 yr old.

NEW & NOTEWORTHY This study shows, for the first time, that maximal oxygen consumption (+13%) and performance (+11%) can still be increased between 101 and 103 yr old with 2 yr of training and that a centenarian is able, at 103 yr old, to cover 26.9 km/h in 1 h.
Neurons derived from different brain regions are inherently different in vitro: a novel multiregional brain-on-a-chip
Authors: Dauth Stephanie , Maoz Ben M. , Sheehy Sean P. , Hemphill Matthew A. , Murty Tara , Macedonia Mary Kate , Greer Angie M. , Budnik Bogdan , Parker Kevin Kit
Published: December 2016

Brain in vitro models are critically important to developing our understanding of basic nervous system cellular physiology, potential neurotoxic effects of chemicals, and specific cellular mechanisms of many disease states. In this study, we sought to address key shortcomings of current brain in vitro models: the scarcity of comparative data for cells originating from distinct brain regions and the lack of multiregional brain in vitro models. We demonstrated that rat neurons from different brain regions exhibit unique profiles regarding their cell composition, protein expression, metabolism, and electrical activity in vitro. In vivo, the brain is unique in its structural and functional organization, and the interactions and communication between different brain areas are essential components of proper brain function. This fact and the observation that neurons from different areas of the brain exhibit unique behaviors in vitro underline the importance of establishing multiregional brain in vitro models. Therefore, we here developed a multiregional brain-on-a-chip and observed a reduction of overall firing activity, as well as altered amounts of astrocytes and specific neuronal cell types compared with separately cultured neurons. Furthermore, this multiregional model was used to study the effects of phencyclidine, a drug known to induce schizophrenia-like symptoms in vivo, on individual brain areas separately while monitoring downstream effects on interconnected regions. Overall, this work provides a comparison of cells from different brain regions in vitro and introduces a multiregional brain-on-a-chip that enables the development of unique disease models incorporating essential in vivo features.

NEW & NOTEWORTHY Due to the scarcity of comparative data for cells from different brain regions in vitro, we demonstrated that neurons isolated from distinct brain areas exhibit unique behaviors in vitro. Moreover, in vivo proper brain function is dependent on the connection and communication of several brain regions, underlining the importance of developing multiregional brain in vitro models. We introduced a novel brain-on-a-chip model, implementing essential in vivo features, such as different brain areas and their functional connections.
Segmental specificity in belly dance mimics primal trunk locomotor patterns
Authors: Nugent Marilee M. , Milner Theodore E.
Published: December 2016

Belly dance was used to investigate control of rhythmic undulating trunk movements in humans. Activation patterns in lumbar erector spinae muscles were recorded using surface electromyography at four segmental levels spanning T10 to L4. Muscle activation patterns for movement tempos of 2 Hz, 3 Hz, and as fast as possible (up to 6 Hz) were compared to test the hypothesis that frequency modulates muscle timing, causing pattern changes analogous to gait transitions. Groups of trained and untrained female subjects were compared to test the hypothesis that experience modifies muscle coordination patterns and the capacity for selective motion of spinal segments. Three distinct coordination patterns were observed. An ipsilateral simultaneous pattern (S) and a diagonal synergy (D) dominated at lower frequencies. The S pattern was selected most often by novices and resembled the standing wave of activation underlying the alternating lateral trunk bending in salamander trotting. At 2 Hz, most trained subjects selected the D pattern, suggesting a greater capacity for segmental specificity compared with untrained subjects. At 3–4 Hz, there emerged an asynchronous pattern (A) analogous to the rostral-caudal traveling wave in salamander and lamprey swimming. The neural networks and mechanisms identified in primitive vertebrates, such as chains of coupled oscillators and segmental crossed inhibitory connections, could explain the patterns observed in this study in humans. Training allows modification of these patterns, possibly through improved capacity for selectively exciting or inhibiting segmental pattern generators.

NEW & NOTEWORTHY Belly dance provides a novel approach for studying spinal cord neural circuits. New evidence suggests that primitive locomotor circuits may be conserved in humans. Erector spinae activation patterns during the hip shimmy at different tempos are similar to those observed in salamander walking and swimming. As movement frequency increases, a sequential pattern similar to lamprey swimming emerges, suggesting that primal involuntary control mechanisms dominate in fast lateral rhythmic spine undulations even in humans.