bluuebunny/crossref_metadata_2025 huggingface dataset:
A 1D pulse wave propagation model of the hemodynamics of calf muscle pump function
Authors: Keijsers J. M. T. , Leguy C. A. D. , Huberts W. , Narracott A. J. , Rittweger J. , van de Vosse F. N.
Published: March 2015

The calf muscle pump is a mechanism which increases venous return and thereby compensates for the fluid shift towards the lower body during standing. During a muscle contraction, the embedded deep veins collapse and venous return increases. In the subsequent relaxation phase, muscle perfusion increases due to increased perfusion pressure, as the proximal venous valves temporarily reduce the distal venous pressure (shielding). The superficial and deep veins are connected via perforators, which contain valves allowing flow in the superficial‐to‐deep direction. The aim of this study is to investigate and quantify the physiological mechanisms of the calf muscle pump, including the effect of venous valves, hydrostatic pressure, and the superficial venous system. Using a one‐dimensional pulse wave propagation model, a muscle contraction is simulated by increasing the extravascular pressure in the deep venous segments. The hemodynamics are studied in three different configurations: a single artery–vein configuration with and without valves and a more detailed configuration including a superficial vein. Proximal venous valves increase effective venous return by 53% by preventing reflux. Furthermore, the proximal valves shielding function increases perfusion following contraction. Finally, the superficial system aids in maintaining the perfusion during the contraction phase and reduces the refilling time by 37%. © 2015 The Authors. International Journal for Numerical Methods in Biomedical Engineering published by John Wiley & Sons Ltd.
Ontology building and maintenance in collaborative virtual environments
Authors: Missikoff Michele , Smith Fabrizio , Taglino Francesco
Published: March 2015

The role of ontologies in the enterprise world is constantly increasing, and they are proving even more necessary in distributed production realities, like in extended logistics, industrial districts, or virtual enterprises. In such realities, a common conceptual basis is necessary to compensate the fragmentation inherent in the underlying industrial models. This paper presents an end‐to‐end framework based on an open, collaborative approach for developing and maintaining business domain ontologies. The framework has been achieved within the European Project BIVEE and has been experimented in two industrial realities: the high‐tech sector of robotics and the more traditional one of furniture. Copyright © 2015 John Wiley & Sons, Ltd.
Distributed containment control of second‐order multiagent systems with input delays under general protocols
Authors: Rong Lina , Shen Hao
Published: March 2015

This article addresses the distributed containment control problem in a group of agents governed by second‐order dynamics with directed network topologies. Considering there are multiple leaders, we study a general second‐order containment controller which can realize several different consensus modes by adjusting control gains. A necessary and sufficient condition on the control gains of the general containment controller is provided. Moreover, the delay sensitivity of the closed‐loop multiagent system under the general containment controller is studied; the maximal upper bound of the constant delays is obtained. Finally, several numerical examples are used to illustrate the theoretical results. © 2015 Wiley Periodicals, Inc. Complexity 21: 112–120, 2016
A discontinuous Galerkin‐based sharp‐interface method to simulate three‐dimensional compressible two‐phase flow
Authors: Fechter S. , Munz C.‐D.
Published: March 2015

A numerical method for the simulation of compressible two‐phase flows is presented in this paper. The sharp‐interface approach consists of several components: a discontinuous Galerkin solver for compressible fluid flow, a level‐set tracking algorithm to follow the movement of the interface and a coupling of both by a ghost‐fluid approach with use of a local Riemann solver at the interface. There are several novel techniques used: the discontinuous Galerkin scheme allows locally a subcell resolution to enhance the interface resolution and an interior finite volume Total Variation Diminishing (TVD) approximation at the interface. The level‐set equation is solved by the same discontinuous Galerkin scheme. To obtain a very good approximation of the interface curvature, the accuracy of the level‐set field is improved and smoothed by an additional PNPM‐reconstruction. The capabilities of the method for the simulation of compressible two‐phase flow are demonstrated for a droplet at equilibrium, an oscillating ellipsoidal droplet, and a shock‐droplet interaction problem at Mach 3. Copyright © 2015 John Wiley & Sons, Ltd.
Stability analysis of a polymer film casting problem
Authors: Kallel A. , Hachem E. , Rapetti F. , Demay Y. , Agassant J. F.
Published: March 2015

The polymer cast film process consists of stretching a molten polymer film between a flat die and a drawing roll. Drawing instabilities are often encountered and represent a drastic limitation to the process. Newtonian fluid film stretching stability is investigated using two numerical strategies. The first one is a ‘tracking’ method, which consists of solving Stokes equations in the whole fluid area (extrusion die and stretching path) by finite elements. The interface is determined to satisfy a kinematic equation. A domain decomposition meshing technique is used in order to account for a flow singularity resulting from the change in the boundary conditions between the die flow region and the stretching path region. A linear stability method is then applied to this transient kinematic equation in order to investigate the stability of the stationary solution. The second method is a direct finite element simulation in an extended area including the fluid and the surrounding air. The time‐dependent interface is captured by solving an appropriate level‐set function. The agreement between the two methods is fair. The influence of the stretching parameters (Draw ratio and drawing length) is investigated. For a long stretching distance, a critical Draw ratio around 20 delimitating stable and unstable drawing conditions is obtained, and this agrees well with the standard membrane models, which have been developed 40 years ago. When decreasing the stretching distance, the membrane model is no longer valid. The 2D models presented here point out a significant increase of the critical Draw ratio, and this is consistent with experimental results. Copyright © 2015 John Wiley & Sons, Ltd.
Explaining Declining Rates of Institutional LTC Use in the Netherlands: A Decomposition Approach
Authors: de Meijer Claudine , Bakx Pieter , van Doorslaer Eddy , Koopmanschap Marc
Published: March 2015

The use of long‐term care (LTC) is changing rapidly. In the Netherlands, rates of institutional LTC use are falling, whereas homecare use is growing. Are these changes attributable to declining disability rates, or has LTC use given disability changed? And have institutionalization rates fallen regardless of disability level, or has LTC use become better tailored to needs? We answer these questions by explaining trends in LTC use for the Dutch 65+ population in the period 2000–2008 using a nonlinear variant of the Oaxaca–Blinder decomposition. We find that changes in LTC use are not due to shifts in the disability distribution but can almost entirely be traced back to changes in the way the system treats disability. Elderly with mild disability are more likely to be treated at home than before, whereas severely disabled individuals continue to receive institutional LTC. As a result, LTC use has become better tailored to the needs for such care. This finding suggests that policies that promote LTC in the community rather than in institutions can effectively mitigate the consequences of population aging on LTC spending. Copyright © 2015 John Wiley & Sons, Ltd.
The Determinants of Care Home Closure
Authors: Allan Stephen , Forder Julien
Published: March 2015

This study investigates the causes of full closure of care homes in the English care home/nursing home market. We develop theoretical arguments about two causes for closure that are triggered by errors or external shocks: poor economic sustainability and regulatory action. Homes aiming to operate with lower quality in the market are argued for a number of reasons to be more susceptible to errors/shocks in setting quality, especially negative errors, leading to an empirical hypothesis that observed quality should negatively affect closure chance. In addition, given quality, homes facing relatively high levels of local competition should also have an increased chance of closure. We use a panel of care homes from 2008 and 2010 to examine factors affecting their closure status in subsequent years. We allow for the potential endogeneity of home quality and use multiple imputation to replace missing data. Results suggest that homes with comparatively higher quality and/or lower levels of competition have less chance of closure than other homes. We discuss that the results provide some support for the policy of regulators providing quality information to potential purchasers in the market. © 2015 The Authors. Health Economics published by John Wiley & Sons Ltd.
Testing the Bed‐Blocking Hypothesis: Does Nursing and Care Home Supply Reduce Delayed Hospital Discharges?
Authors: Gaughan James , Gravelle Hugh , Siciliani Luigi
Published: March 2015

Hospital bed‐blocking occurs when hospital patients are ready to be discharged to a nursing home, but no place is available, so that hospital care acts as a more costly substitute for long‐term care. We investigate the extent to which greater supply of nursing home beds or lower prices can reduce hospital bed‐blocking using a new Local Authority (LA) level administrative data from England on hospital delayed discharges in 2009–2013. The results suggest that delayed discharges respond to the availability of care home beds, but the effect is modest: an increase in care home beds by 10% (250 additional beds per LA) would reduce social care delayed discharges by about 6–9%. We also find strong evidence of spillover effects across LAs: more care home beds or fewer patients aged over 65 years in nearby LAs are associated with fewer delayed discharges. © 2015 The Authors. Health Economics Published by John Wiley & Sons Ltd.
ErgoVSM: A Tool for Integrating Value Stream Mapping and Ergonomics in Manufacturing
Authors: Jarebrant Caroline , Winkel Jörgen , Johansson Hanse Jan , Mathiassen Svend Erik , Öjmertz Birgitta
Published: March 2015

Value stream mapping (VSM) is a lean tool aiming at waste reduction. Previous research suggests that the use of VSM may result in work intensification and thus an increased risk for the workers of developing work‐related musculoskeletal disorders (MSD). In the current study, VSM was developed to also consider physical exposure in the analyzed production system (ErgoVSM). As the VSM, ErgoVSM is based on a participatory approach. ErgoVSM was tested in a Swedish manufacturing company. The results suggest that ErgoVSM catalyzes change processes to include intervention proposals emphasizing ergonomics in addition to waste reduction. Thus, ErgoVSM appeared useful for the investigated target group of production engineers and experienced operators. The performance improvements suggested when using the ordinary VSM seemed not to be hampered by adding the ergonomics complement. However, the use of ErgoVSM was somewhat more time consuming than the use of VSM. In conclusion, ErgoVSM is suggested as a feasible tool to be used by production engineers and experienced operators for including ergonomics considerations in the rationalization process.
Prediction of chronic lymphocytic leukaemia incidence in Germany and of patients ineligible for standard chemotherapy
Authors: Eisemann Nora , Schnoor Maike , Katalinic Alexander
Published: March 2015

Chronic lymphocytic leukaemia (CLL) patients often remain asymptomatic for several years after diagnosis. When the disease becomes symptomatic or progressive, chemotherapy with fludarabine in combination with an anti‐CD20 antibody (FCR) is recommended as standard therapy, except for patients with relevant comorbidity or with del(17p13) oder TP53 mutation. We predict the number of prevalent CLL patients in 2011–2020 who need first‐line therapy but are ineligible for FCR treatment. The input parameters of the Markov model are the estimated total CLL incidence (based on German cancer registry data) and clinical data on disease progression and patient characteristics (obtained by a systematic literature research). Plausibility ranges for the estimation of the total CLL incidence are given by the following: (1) inclusion of small lymphocytic lymphoma and (2) an alternative handling of death‐certificate‐only cases. The number of patients ineligible for FCR treatment increases from approximately 1200 in 2011 to approximately 1450 in 2020. The inclusion of small lymphocytic lymphoma cases results in 10% higher estimates, the alternative handling of death‐certificate‐only cases in 8% lower estimates. Recently, several new and targeted agents have been approved for CLL patients ineligible for standard treatment. Estimation of patient numbers is a prerequisite for planning of health care and for calculating the costs of treatment. Copyright © 2015 John Wiley & Sons, Ltd.
Rate and predictors of non‐response to first‐line antipsychotic treatment in first‐episode schizophrenia
Authors: Chiliza Bonginkosi , Asmal Laila , Kilian Sanja , Phahladira Lebogang , Emsley Robin
Published: March 2015

Objective

The goals of this study were to (i) estimate the rate of non‐response to first‐line treatment in first‐episode schizophrenia, (ii) evaluate other outcomes associated with symptom non‐response and (iii) identify demographic, baseline clinical and early treatment response predictors of non‐response.

Methods

This was a single‐site, longitudinal cohort study assessing the effects of treatment with flupenthixol decanoate according to a standardised protocol over 12 months in patients with schizophrenia, schizophreniform and schizo‐affective disorders.

Results

Of 126 patients who received at least one dose of study medication, 84 (67%) completed the study. Fifteen (12%) met our predefined criteria for non‐response. Non‐responders were younger and at baseline had more prominent disorganised symptoms, poorer social and occupational functioning, poorer quality of life for psychological, social and environmental domains, more prominent neurological soft signs (NSS) and lower body mass index. At endpoint, the non‐responders were characterised by higher levels of symptomatology in all domains, poorer functional outcome, poorer quality of life and greater cognitive impairments. They also had more prominent NSS and lower body mass index. The strongest predictors of non‐response were more prominent baseline NSS and poor early (7 weeks) treatment response.

Conclusions

Results are consistent with a lower rate of refractoriness to treatment in first‐episode schizophrenia compared with multi‐episode samples. Copyright © 2015 John Wiley & Sons, Ltd.
Modelling Sphagnum moisture stress in response to projected 21st‐century climate change
Authors: Moore P. A. , Waddington J. M.
Published: March 2015

Sphagnum moss is an important genus of plants responsible for large stores of soil organic carbon associated with wet habitats, such as northern peatlands. Northern peatlands, which contain globally significant quantities of legacy carbon, may be vulnerable to enhanced summer moisture deficits due to climate change. We adapted HYDRUS‐1D and a semi‐arid soil‐moisture model to investigate the role of microtopographic position and depth dependence of peat hydraulic properties on Sphagnum moisture‐stress response to current and projected climate conditions in an idealized northern Michigan peatland. Water table (WT) level was shown to have a strong control on pore‐water pressure (ψ) and thus on Sphagnum moisture stress. As a result of the close correspondence between surface peat hydraulic properties for hummocks and hollows used to parameterize our model, the microtopographic position was shown to have a greater impact on Sphagnum moisture stress. Model behaviour suggests that, while ψ maintains equilibrium‐profile values relative to the WT level for relatively shallow values, surface ψ becomes nonlinearly related to the WT level below a value of approximately −0.4 m, thus, greatly increasing the likelihood of desiccation under future climate scenarios, where growing‐season soil‐moisture deficits are projected to increase. The simulated range of instantaneous and cumulative moisture stress for hollows under future climate conditions closely corresponds to the contemporary range exhibited by hummocks. Therefore, in order to assess the competitive advantage of various Sphagnum species to future climate conditions, we argue that more data are needed to better inform a physiological ψ‐based moisture‐stress threshold, the evolution of the stress response to increasing levels of desiccation and its subsequent recovery dynamics. Copyright © 2015 John Wiley & Sons, Ltd.
NEIGHBORHOOD DISORDER, PERCEPTIONS OF NEIGHBORHOOD SOCIAL CAPITAL, AND MATERNAL STRESS: EXPLORATION OF A MEDIATING MECHANISM
Authors: Zhang Saijun , Eamon Mary Keegan , Zhan Min
Published: March 2015

Stress is a critical precipitant of depression and other symptoms of mental disorder, and it is especially a concern for single mothers, given their vulnerability to various stressors. Although there is emerging research interest in parenting stress issues, few studies have examined the association between neighborhood environment and maternal stress. Even fewer studies have examined the mechanism that contributes to this relationship. Using data from a national study, the current study investigates relationships among neighborhood disorder, perceived social capital, and maternal stress among a sample of single mothers. The study finds that neighborhood disorder is positively associated with single mothers’ maternal stress, and this relationship is mediated by these mothers’ perceived social capital in the neighborhood. The findings suggest the importance of considering responsive policies and strategies to buffer the detrimental effect of problematic neighborhood environments on single mothers’ social capital, which should in turn decrease maternal stress.
FINANCIAL STRESS, NEIGHBORHOOD STRESS, AND WELL‐BEING: MEDIATIONAL AND MODERATIONAL MODELS
Authors: Montpetit Mignon A. , Kapp Amy E. , Bergeman C.S.
Published: March 2015

This study explores whether high quality neighborhoods or social integration have protective effects on psychological well‐being, especially in the face of financial challenges. Previous research suggests that low levels of financial stress, lower neighborhood stress, and social integration are each associated with greater levels of well‐being; few studies, however, investigate these contextual variables in confluence. Data from the Notre Dame Study of Health and Well‐Being were used to investigate whether (a) neighborhood stress mediates the relationship between financial stress and psychological well‐being and (b) social integration moderates the relationship between neighborhood stress and psychological well‐being. Results were consistent with both hypotheses and were replicated in data from Successful Aging in Context. These results suggest that proximal contextual variables, such as social integration and neighborhood stress can arbitrate the effect that less proximal contextual variables, such as economic conditions, have on individuals’ psychological well‐being.
A thermo‐alkaline lipase from a new thermophile Geobacillus thermodenitrificans AV‐5 with potential application in biodiesel production
Authors: Christopher Lew P , Zambare Vasudeo P , Zambare Archana , Kumar Hemanathan , Malek Ladislav
Published: March 2015

BACKGROUND

A thermophilic lipase‐producing Geobacillus thermodenitrificans strain AV‐5 was isolated from the Mushroom Spring of Yellowstone National Park in WY, USA and studied as a source of lipase for transesterification of vegetable oils to biodiesel.

RESULTS

A maximum activity of 330 U mL−1 was produced on 2% (v/v) waste cooking oil at 50 °C, pH 8, aeration rate of 1 vvm and agitation speed of 400 rpm. However, the higher lipase productivity (14.04 U mL−1 h−1) was found at a volumetric oxygen transfer coefficient (kLa) value of 18.48 h−1. The partially purified lipase had a molecular weight, temperature and pH optimum of 50 kDa, 65 °C and pH 9, respectively, and was thermo‐alkali stable: at 70 °C, it retained 81% activity and 45% stability; at pH 10 it lost only 15% and 2.6% of its maximum activity and stability, respectively. Enzyme kinetic studies with p‐nitrophenyl laurate as substrate revealed high substrate specificity (km of 0.440 mmol L−1) and kinetic activity (vmax of 556 nmol mL min−1) of lipase.

CONCLUSIONS

The kLa was found to be highly dependent on aeration and agitation rates. Following optimization of fermentation medium and parameters, a 7.5‐fold increase in lipase production by G. thermodenitrificans was attained. The lipase activity and substrate specificity (as km) are among the highest reported in the literature for bacterial lipases. It was demonstrated that the enzyme can produce biodiesel from waste cooking oil with a conversion yields of 76%. © 2015 Society of Chemical Industry
Bone marrow‐derived progenitor cells in de novo liver regeneration in liver transplant
Authors: Lee Sung‐Gyu , Moon Sung‐Hwan , Kim Hee‐Je , Lee Ji Yoon , Park Soon‐Jung , Chung Hyung‐Min , Ha Tae‐Yong , Song Gi‐Won , Jung Dong‐Hwan , Park Hojong , Kwon Tae‐Won , Cho Yong‐Pil
Published: March 2015

The study was designed (1) to examine the hypothesis that circulating progenitor cells play a role in the process of de novo regeneration in human liver transplants and that these cells arise from a cell population originating in, or associated with, the bone marrow and (2) to investigate whether the transplanted liver volume has an effect on the circulating recipient‐derived progenitor cells that generate hepatocytes during this process. Clinical data and liver tissue characteristics were analyzed in male individuals who underwent sex‐mismatched adult‐to‐adult living donor liver transplantation using dual left lobe grafts. Dual left lobe grafts were examined at the time of transplantation and 19 to 27 days after transplantation. All recipients showed recovery of normal liver function and a significant increase in the volume of the engrafted left lobes after transplantation. Double staining for a Y‐chromosome probe and the CD31 antigen showed the presence of hybrid vessels composed of recipient‐derived cells and donor cells within the transplanted liver tissues. Furthermore, CD34‐expressing cells were observed commingling with Y‐chromosome+ cells. The ratio of recipient‐derived vessels and the number of Y+CD34+ cells tended to be higher when smaller graft volumes underwent transplantation. These findings suggest that the recruitment of circulating bone marrow–derived progenitor cells could contribute to vessel formation and de novo regeneration in human liver transplants. Moreover, graft volume may be an important determinant for the active mobilization of circulating recipient‐derived progenitor cells and their contribution to liver regeneration. Liver Transpl 21:1186–1194, 2015. © 2015 AASLD.
Zooming in on the small: The plasticity of striatal dendritic spines in l‐DOPA–Induced dyskinesia
Authors: Fieblinger Tim , Cenci M. Angela
Published: March 2015

The spiny dendrites of striatal projection neurons integrate synaptic inputs of different origins to regulate movement. It has long been known that these dendrites lose spines and display atrophic features in Parkinson's disease (PD), but the significance of these morphological changes has remained unknown. Some recent studies reveal a remarkable structural plasticity of striatal spines in parkinsonian rodents treated with L‐3,4‐dihydroxyphenylalanine (L‐DOPA), and they demonstrate an association between this plasticity and the development of dyskinesia. These studies used different approaches and animal models, which possibly explains why they emphasize different plastic changes as being most closely linked to dyskinesia (such as a growth of new spines in neurons of the indirect pathway, or a loss of spines in neurons of the direct pathway, or the appearance of spines with aberrant synaptic features). Clearly, further investigations are required to reconcile these intriguing findings and integrate them in a coherent pathophysiological model. Nevertheless, these studies may mark the beginning of a new era for dyskinesia research. In addition to addressing neurochemical and molecular events that trigger involuntary movements, there is a need to better understand the long‐lasting structural reorganization of cells and circuits that maintain the brain in a “dyskinesia‐prone” state. This may lead to the identification of new efficacious approaches to prevent the complications of dopaminergic therapies in PD. © 2015 International Parkinson and Movement Disorder Society
Renin‐Angiotensin System: An Old Player with Novel Functions in Skeletal Muscle
Authors: Cabello‐Verrugio Claudio , Morales María Gabriela , Rivera Juan Carlos , Cabrera Daniel , Simon Felipe
Published: March 2015

Skeletal muscle is a tissue that shows the most plasticity in the body; it can change in response to physiological and pathological stimuli. Among the diseases that affect skeletal muscle are myopathy‐associated fibrosis, insulin resistance, and muscle atrophy. A common factor in these pathologies is the participation of the renin‐angiotensin system (RAS). This system can be functionally separated into the classical and nonclassical RAS axis. The main components of the classical RAS pathway are angiotensin‐converting enzyme (ACE), angiotensin II (Ang‐II), and Ang‐II receptors (AT receptors), whereas the nonclassical axis is composed of ACE2, angiotensin 1–7 [Ang (1–7)], and the Mas receptor. Hyperactivity of the classical axis in skeletal muscle has been associated with insulin resistance, atrophy, and fibrosis. In contrast, current evidence supports the action of the nonclassical RAS as a counter‐regulator axis of the classical RAS pathway in skeletal muscle. In this review, we describe the mechanisms involved in the pathological effects of the classical RAS, advances in the use of pharmacological molecules to inhibit this axis, and the beneficial effects of stimulation of the nonclassical RAS pathway on insulin resistance, atrophy, and fibrosis in skeletal muscle.
Hopf‐pitchfork bifurcation in a two‐neuron system with discrete and distributed delays
Authors: Wang Hongbin , Wang Jingnan
Published: March 2015

Both discrete and distributed delays are considered in a two‐neuron system. We analyze the influence of interaction coefficient and time delay on the Hopf‐pitchfork bifurcation. First, we obtain the codimension‐2 unfolding with original parameters for Hopf‐pitchfork bifurcation by using the center manifold reduction and the normal form method. Next, through analyzing the unfolding structure, we give complete bifurcation diagrams and phase portraits, in which multistability and other dynamical behaviors of the original system are found, such as a stable periodic orbit, the coexistence of two stable nontrivial equilibria, and the coexistence of a stable periodic orbit and two stable equilibria. In addition, the obtained theoretical results are verified by numerical simulations. Finally, we perform the comparisons of the obtained results of Hopf‐pitchfork bifurcation with other Hopf‐fold bifurcation results in some biological neural systems and give the obtained mathematical results corresponding to the physical states of neurons. Copyright © 2015 JohnWiley & Sons, Ltd.
Plasmon resonance and heat generation in nanostructures
Authors: Fang Xiaoping , Deng Youjun , Li Jing
Published: March 2015

In this paper, the photothermal effects of plasmon resonance are investigated. Metal nanoparticles efficiently generate heat in the presence of electromagnetic radiation. The process is strongly enhanced when a fixed frequency of the incident wave illuminates on nanoparticles such that plasmon resonance happens. We introduce the electromagnetic radiation model and show exactly how and when the plasmon resonance happens. We then construct the heat generation and transfer theory and derive the heat effect induced by plasmon resonance. Finally, the heat generation under plasmon resonance in a concentric nanoshell structure is considered specially, and excited result is obtained. Copyright © 2015 John Wiley & Sons, Ltd.
Stability and Hopf bifurcation of a delayed virus infection model with Beddington–DeAngelis infection function and cytotoxic T‐lymphocyte immune response
Authors: Yang Yu
Published: March 2015

In this paper, a class of virus infection model with Beddington–DeAngelis infection function and cytotoxic T‐lymphocyte immune response is investigated. Time delay in the immune response term is incorporated into the model. We show that the dynamics of the model are determined by the basic reproduction number
and the immune response reproduction number
. If
, then the infection‐free equilibrium is globally asymptotically stable. If
, then the immune‐free equilibrium is globally asymptotically stable. If
, then the stability of the interior equilibrium is investigated. We conclude that Hopf bifurcation occurs as the time delay passes through a critical value. Numerical simulations are carried out to support our theoretical conclusion well. Copyright © 2015 John Wiley & Sons, Ltd.
Enhancing k‐space quantitative susceptibility mapping by enforcing consistency on the cone data (CCD) with structural priors
Authors: Wen Yan , Wang Yi , Liu Tian
Published: March 2015

Purpose

The inversion from the magnetic field to the magnetic susceptibility distribution is ill‐posed because the dipole kernel, which relates the magnetic susceptibility to the magnetic field, has zeroes at a pair of cone surfaces in the k‐space, leading to streaking artifacts on the reconstructed quantitative susceptibility maps (QSM). A method to impose consistency on the cone data (CCD) with structural priors is proposed to improve the solutions of k‐space methods.

Methods

The information in the cone region is recovered by enforcing structural consistency with structural prior, while information in the noncone trust region is enforced to be consistent with the magnetic field measurements in k‐space. This CCD method was evaluated by comparing the initial results of existing QSM algorithms to the QSM results after CCD enhancement with respect to the COSMOS results in simulation, phantom, and in vivo human brain.

Results

The proposed method demonstrated suppression of streaking artifacts and the resulting QSM showed better agreement with reference standard QSM compared with other k‐space based methods.

Conclusion

By enforcing consistency with structural priors in the cone region, the missing data in the cone can be recovered and the streaking artifacts in QSM can be suppressed. Magn Reson Med 75:823–830, 2016. © 2015 Wiley Periodicals, Inc.
Cut Mark Cluster Geometry and Equifinality in Replicated Early Stone Age Butchery
Authors: Merritt S. R.
Published: March 2015

Early Stone Age cut marks created during tool‐assisted carnivory potentially offer inferences into hominin butchery behaviour and access to complete or defleshed carcasses. Actualistic butchery trials of 16 goat and cow half‐carcasses were completed by an experienced butcher with replicated Oldowan tools to investigate how the geometric organisation of cut mark clusters reflects flake versus core tool use and bulk muscle versus scrap defleshing. A cluster of cut marks is defined as a series of adjacent cut mark striations that occur at an anatomical location and are bounded by unmarked cortical surface. Tool type and butchery action were predicted to differentially mark certain long bone portions and influence cluster attributes. Moulds of 613 cut mark clusters were photographed and measured using ImageJ software (National Institutes of Health, Bethesda, Maryland, USA) for cluster area, cut mark count, median cut mark length and standard deviation of cut mark length and angle. Analysis suggests the following results: (i) cluster attributes are correlated;(ii) changes in cluster geometry are related to increasing cut mark count and length but not tool type or defleshed muscle amount; (iii) large clusters occur on large animals; and (iv) long bone midshaft portions are cut‐marked during both bulk and scrap muscle defleshing. Analysis of 179 cut mark clusters on long bone shafts of sizes 1–4 mammals from three Okote member assemblages at Koobi Fora, Kenya, shows that archaeological clusters have a similar number of marks when compared with experimental clusters but are significantly smaller, have shorter median marks and include less deviation in mark length and angle. Archaeological clusters corroborate that increasing area is positively correlated with cut mark count, median mark length and standard deviation of mark length and angle. A quantitative inferential model that links cut mark cluster geometry to tool type or the amount of muscle defleshed is not supported by these data. Copyright © 2015 John Wiley & Sons, Ltd.
Comparison of administrative/billing data to expected protocol‐mandated chemotherapy exposure in children with acute myeloid leukemia: A report from the Children's Oncology Group
Authors: Miller Tamara P. , Troxel Andrea B. , Li Yimei , Huang Yuan‐Shung , Alonzo Todd A. , Gerbing Robert B. , Hall Matt , Torp Kari , Fisher Brian T. , Bagatell Rochelle , Seif Alix E. , Sung Lillian , Gamis Alan , Rubin David , Luger Selina , Aplenc Richard
Published: March 2015

Background

Recently investigators have used analysis of administrative/billing datasets to answer clinical and pharmacoepidemiology questions in pediatric oncology. However, the accuracy of pharmacy data from administrative/billing datasets have not yet been evaluated. The primary objective of this study was to determine the concordance of Pediatric Health Information System (PHIS) administrative/billing chemotherapy data with Children's Oncology Group (COG) protocol‐mandated chemotherapy and to assess the implications of this level of concordance for further PHIS research.

Procedure

Data from 384 pediatric patients (1,060 courses of chemotherapy) with acute myeloid leukemia treated on COG clinical trial AAML0531 were previously merged with PHIS data. PHIS chemotherapy administrative/billing data were reviewed for the first three courses of chemotherapy. Accuracy was assessed using three metrics: recognizability of chemotherapy pattern by course, chemotherapy administration pattern by individual medication, and concordance with the number of days of protocol‐defined chemotherapy.

Results

The chemotherapy pattern was recognizable in 87.3% of courses when course‐wide accuracy was assessed. Chemotherapy administration pattern varied by medication. Cytarabine had perfect concordance 70.9% of the time, daunorubicin had perfect concordance 77.4% of the time, and etoposide had perfect concordance 67.8% of the time.

Conclusions

The accuracy of chemotherapy administrative/billing data supports the continued use of PHIS data for epidemiology studies as long as investigators perform data quality control checks and evaluate each specific medication prior to undertaking definitive analyses. Pediatr Blood Cancer 2015;62:1184–1189. © 2015 Wiley Periodicals, Inc.
Gastrointestinal symptoms and pancreatic exocrine insufficiency in type 1 and type 2 diabetes
Authors: Cummings Michael H , Chong Lina , Hunter Victoria , Kar Partha S , Meeking Darryl R , Cranston Iain CP
Published: March 2015

Our review of clinical practice demonstrates that gastrointestinal (GI) symptoms were common in patients with type 1 and type 2 diabetes seen within our diabetes service. In those patients who are symptomatic, we observed that 42% had low faecal elastase 1 levels consistent with the diagnosis of pancreatic exocrine insufficiency (PEI). The presence of steatorrhoea and weight loss alone were insufficient to screen for PEI, and other GI symptoms (such as diarrhoea, abdominal cramps/pain and bloating) need to be additionally sought. Copyright © 2015 John Wiley & Sons, Ltd.
A proteomic approach to discover and compare interacting partners of papillomavirus E2 proteins from diverse phylogenetic groups
Authors: Jang Moon Kyoo , Anderson D. Eric , van Doorslaer Koenraad , McBride Alison A.
Published: March 2015

Papillomaviruses are a very successful group of viruses that replicate persistently in localized regions of the stratified epithelium of their specific host. Infection results in pathologies ranging from asymptomatic infection, benign warts, to malignant carcinomas. Despite this diversity, papillomavirus genomes are small (7–8 kbp) and contain at most eight genes. To sustain the complex papillomaviral life cycle, each viral protein has multiple functions and interacts with and manipulates a plethora of cellular proteins. In this study, we use tandem affinity purification and MS to identify host factors that interact with 11 different papillomavirus E2 proteins from diverse phylogenetic groups. The E2 proteins function in viral transcription and replication and correspondingly interact with host proteins involved in transcription, chromatin remodeling and modification, replication, and RNA processing.
BAlN thin layers for deep UV applications
Authors: Li Xin , Sundaram Suresh , Gmili Youssef El , Moudakir Tarik , Genty Frédéric , Bouchoule Sophie , Patriarche Gilles , Dupuis Russell D. , Voss Paul L. , Salvestrini Jean‐Paul , Ougazzaden Abdallah
Published: March 2015

In this work, wurtzite BAlN layers with boron composition as high as 12% were successfully grown by MOVPE. The growth was performed at 650 °C and then annealed at 1020 °C. Low temperature growth was used in order to alleviate B‐rich phase poisoning under high TEB/III ratio. The growth was performed by continuous epitaxy as well as by flow‐modulate epitaxy. BAlN single layers with clearly defined X‐ray diffraction peaks were achieved on AlN templates which are appropriate substrates for deep UV devices, as well as on GaN templates to facilitate distinguishing of the XRD peak of BAlN from the substrate peak. The layer demonstrated columnar crystalline features and inherited wurtzite structure from substrates.

Cross‐section STEM image (bright field) of 75 nm thick BAlN layers containing 12% boron taken along the [11−2 0] zone axis. Zone A is lattice‐oriented along c‐axis and zone B has columnar structure; (b) higher magnification image for the top part of the layer; (c) higher magnification image for the film/substrate interface.
High quality thick InGaN nanostructures grown by nanoselective area growth for new generation photovoltaic devices
Authors: Sundaram Suresh , Puybaret Renaud , Li Xin , El Gmili Youssef , Streque Jeremy , Panztas Konstantinos , Orsal Gaelle , Patriarche Gilles , Voss Paul L. , Salvestrini Jean Paul , Ougazzaden Abdallah
Published: March 2015

Nanoselective area growth (NSAG) of thick InGaN nanopyramid and nanostripe arrays was demonstrated using metal organic chemical vapor deposition. SiO2 nanopattern masks were fabricated using a simple and industry friendly e‐beam lithography process. One hundred nanometer thick InGaN is grown with perfect selectivity over patterned GaN templates. InGaN nanostructures are homogenously pyramidal in shape, are mostly free from intrinsic material defects, and show six smooth semipolar facets. Catholuminescence emission peaks from the nanostructures are stronger than those from planar InGaN, which is due to improvement in crystal quality. The emission peaks from nanostructures are considerably redshifted from 397 to 425 nm, confirming increase in In incorporation in the nanostructures from 7 to 9% indium in InGaN. The ability to incorporate more indium depending on the geometry of the patterns and to grow selectively defect‐free thick InGaN nanostructures via a simple patterning process offers a new route to develop monolithic InGaN‐based high efficiency solar cells.
Insecure Attachment Style and Dysfunctional Sexual Beliefs Predict Sexual Coercion Proclivity in University Men
Authors: Dang Silvain S. , Gorzalka Boris B.
Published: March 2015

Introduction

Past studies have shown an association between low sexual functioning and engaging in sexually coercive behaviors among men. The mechanism of this relationship is not well understood. Moreover, most studies in this area have been done in incarcerated sex offenders.

Aims

The aim of the current study was to investigate the role of potential distal predictors of sexual coercion, including insecure attachment style and dysfunctional sexual beliefs, in mediating the relationship between sexual functioning and sexual coercion. The study also seeks to extend past findings to a novel non-forensic population.

Methods

Male university students (N = 367) anonymously completed online questionnaires.

Main Outcome Measures

Participants completed the Sexual Experiences Survey, Improved Illinois Rape Myth Acceptance Scale, Hostility Towards Women Scale, Likelihood of Rape Item, Experiences in Close Relationships Scale, Dysfunctional Sexual Beliefs Scale, and Brief Sexual Functioning Questionnaire.

Results

Sexual functioning was not significantly associated with sexually coercive behaviors in our sample (r = 0.08, P = 0.247), though a significant correlation between sexual functioning and rape myth acceptance was found (r = 0.18, P = 0.007). Path analysis of all variables showed that the likelihood of rape item was the strongest correlate of sexually coercive behaviors (β = 0.34, P < 0.001), while dysfunctional sexual beliefs appeared to mediate the association between anxious attachment and likelihood of rape item score. Anxious (r = −0.27, P = 0.001) and avoidant (r = −0.19, P = 0.004) attachment also correlated significantly with lower sexual functioning.

Conclusions

These findings suggest the relationship between sexual functioning and sexual coercion may be less robust than previously reported, and may be due to a shared association with other factors. The results elaborate on the interrelation between attachment style and dysfunctional sexual beliefs as predictors of sexual coercion proclivity, suggesting avenues for further research.
Collaborative tools: computer science students' skills versus software industry needs
Authors: Medina‐Dominguez Fuensanta , Sanchez‐Segura Maria‐Isabel , Moreno Ana , Santin Daniel
Published: March 2015

Software companies encourage and further the use of collaborative tools and skills at the work place in pursuit of the benefits of their use: they improve communication, productivity and efficiency, and competitiveness. Besides, undergraduate and graduate software engineering computing curricula recommend subjects related to effective cooperative working and group learning. In order to align industry needs and curricula recommendations, universities should provide graduates with the collaborative knowledge and skills that will be required when they finish their degrees and join the labor market. In this scenario, we asked three questions: Are collaborative tools beneficial to software projects? Is it easier for graduates with knowledge and skills of collaborative tools to find a job? Do enterprises use collaborative tools as a marketing strategy for the recruitment process or are they really empowering their employees to use collaborative tools? We devised a survey which was administered to 86 recent computer science graduates. We applied statistical techniques to analyze the responses. We conclude that graduates skilled in the use of collaborative tools do find it easier to get jobs, and companies are not only looking for people with collaborative skills but also regularly use collaborative tools in their work processes. Copyright © 2015 John Wiley & Sons, Ltd.
Collaborative Teaching: How Does It Work in a Graduate TEFL Class?
Authors: Khabiri Mona , Marashi Hamid
Published: March 2015

Collaborative teaching is a dynamic process in which educators are continuously engaged in restrategizing to fit their curricular goal. This article aims to describe how the use of collaborative teaching in a course on proposal writing benefited a group of graduate students studying teaching English as a foreign language. Throughout the study, two educators jointly planned the course and provided guidelines to the participants on how to choose a topic for research, develop it into a well‐structured written proposal, present it to class, negotiate it with their classmates, and provide feedback to each other's presentations. They also collaboratively provided the students with critical feedback on each step of the above activities. Moreover, the assessment of the course was designed and implemented collaboratively, including assessment of the students' two oral presentations of their proposals, their final written proposals, and the survey of their opinion through a questionnaire. The results indicated the participants' improvement in terms of writing their proposals as compared to each of their oral presentations, their acknowledgment of collaborative teaching, and its impact on increasing their motivation as well as tendency for both collaborative and competitive learning.
Maternal obesity affects fetal myocardial function as early as in the first trimester
Authors: Ingul C. B. , Lorås L. , Tegnander E. , Eik‐Nes S. H. , Brantberg A.
Published: March 2015

Objective

To investigate cardiac function from 14 weeks' gestation in fetuses of obese pregnant women (FOW). Animal studies have shown that maternal obesity induces fibrosis in fetal myocardium. We hypothesized that fetal cardiac function would be impaired among FOW.

Methods

A case–control study with longitudinal follow‐up was performed at Trondheim University Hospital, Norway. In total, 80 pregnant women were included and the final population comprised 52 obese and 24 of normal weight (mean body mass index before pregnancy, 34.8 ± 4.1 vs 21.0 ± 2.2 kg/m2; P < 0.001). The main outcome measures were global strain rate (GSR) and strain by tissue Doppler imaging, tissue Doppler velocities (TDVs) and interventricular septal thickness assessed by fetal echocardiography at gestational ages of 14, 20 and 32 weeks.

Results

In FOW, fetal left ventricle (LV) and right ventricle (RV) GSR and strain were significantly lower than in fetuses of normal‐weight pregnant women: LV GSR was 33.3% lower at 14 weeks, 22.4% lower at 20 weeks and 22.8% lower at 32 weeks of gestation (P < 0.001) with no difference in fetal heart rate. Systolic and late diastolic TDVs for LV were significantly lower from 20 weeks' gestation and remained lower throughout pregnancy. Fetal interventricular septum was 26.6% (P < 0.001) thicker in late pregnancy in FOW compared with normal‐weight pregnancies.

Conclusions

At 14 weeks of gestation, we detected fetal myocardial dysfunction with reduced LV and RV GSR and strain in FOW compared with fetuses of women with normal weight. Our finding is alarming considering the high prevalence of obesity and may partly explain the predisposition of offspring to cardiovascular disease later in life. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.