bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensing characteristics of in‐line Mach‐Zehnder interferometer based on magnetic fluid‐filled multimode photonic crystal fiber
Authors: Luo Jian‐hua , Zhang Gui , Gu Yanran , Gong Shuhang , Quan Guofan , Xie Nanjie , Wang Tianxi
Published: April 2014

An in‐line Mach–Zehnder interferometer (MZI) with a magnetic fluid‐filled multimode photonic crystal fiber (PCF) fusion spliced into two standard optical fibers was proposed. The interference is induced by the two core mode LP01 and LP11 due to the special air hole structure of PCF, which is insensitive to bending and the surrounding refractive index (SRI). High strain sensitivity of 3.7 pm/µε at 1290 nm is achieved. The temperature sensitivity (7.6 pm/°C) is even lower than fiber Bragg grating (FBG). In addition, interference intensity of MZI is sensitive to magnetic field intensity. This structure provides a property for simultaneous measurement of strain and magnetic field and avoiding cross sensitivity on temperature and SRI with a simple process and low cost. Cascading other sensing element such as FBG, LPFG, it also provides a property for simultaneous measurement of multiparameters. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1720–1724, 2014
Index‐insensitive curvature sensor based on holey fiber modal interferometer
Authors: Guan Shouhua , Yu Qingxu
Published: April 2014

An optical fiber curvature sensor based on holey fiber (HF) modal interferometer is demonstrated experimentally. The sensor is fabricated by a length of 2.4 cm HF which is spliced between two single mode fibers. Different resonant peaks have different curvature characteristics, and the sensitivity of 1.815 nm m−1 is achieved in the range of 0–0.905 m−1 for the peak around 1504 nm. The sensor is insensitive to the surrounding refractive index, so it is more suitable for index‐insensitive wavelength‐dependent curvature measurement. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1709–1711, 2014
Reconfigurable microstrip annular ring antenna for circular polarization diversity
Authors: Pyo Seongmin , Kim Nam , Kim Joung‐Myoun
Published: April 2014

This article presents a novel design of a microstrip annular ring antenna with reconfigurable circular polarization (CP) diversity by switching one corner perturbation segment. The proposed antenna has a construction of a single‐feed annular ring as a radiator and frequency perturbing elements at one diagonal edge. To achieve the condition with left‐ and right‐handed CP diversity, the perturbations of the proposed antenna uses the concept of positively and negatively slot‐loaded annular ring. By controls of two diodes' states in the perturbation, both of CP senses have been easily alternated. The simulated and measured results show good and symmetrical radiation patterns at each resonant frequency. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1706–1709, 2014
Erratum: Fields produced at any distance by a Hertzian dipole – generalizations – approximations
Authors: M. Knop Charles
Published: April 2014

The exact integral expressions for the azimuthal magnetic field, Hφ (r/h,θ), and the polar electric field, Eθ (r/h, θ), produced at any polar‐angle, θ, and at any distance, r, from the center of a Hertzian dipole of height h were recently derived‐reported in this journal (Knop, Microwave Opt Technol Lett 54 (2012), 1970–1975). Numerical computations‐plots of these fields as a function of the polar angle θ with the distance parameter of r/h were there given for the case of a dipole of h/λ = 0.10, where λ is the free space operating wavelength. These computations‐plots are here extended to the cases of h/λ = 0.05 and 0.01. Computations and plots of these fields as a function of r/h with θ as a parameter are also given. Critical comparisons to the h/λ = 0.10 case are then made and generalizations formed for the fields' behavior as h/λ decreases. Approximate closed‐form equations/formulas for the fields are also presented.
2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2726–2734, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27881.
2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1728–1729, 2014
Erratum: Electromagnetic bandgap resonators synthesized using ceramic injection molding
Authors: Henderson Rashaunda , Tang Zhizhong , Liu Shaojun , Petras Michael , Aberle James P. , Newman Nathan
Published: April 2014

Originally published in Microwave Opt Technol Lett 56: 371–375, 2014. © 2014 Wiley Periodicals, Inc. View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.28113. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1727–1728, 2014
Planar patch antenna with 100‐μm slit for size reduction and dual‐band applications
Authors: Bordoloi Anup Kr. , Borah Pranjal , Bhattacharyya Satyajib , Bhattacharyya Nidhi S.
Published: April 2014

Planar patch antenna with a 100‐µm slit parallel to radiating edge is designed resulting in significant size reduction of 76% and dual‐frequency operation. Tuning in the frequency range of 2.33–2.78 GHz is achieved for the lower operating frequency by introducing partial slit of varying lengths with comparable size reduction. The upper resonant frequency is higher than the resonant frequency of the simple patch by about 15–20% which is also tunable in the frequency range of 4.9–5.11 GHz, albeit not independently of the lower frequency. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1725–1726, 2014
Erratum: Frequency selective surface with switchable polarization
Authors: Du Guohong , Yu Chengyang , Liu Changjun
Published: April 2014

This article presents a novel frequency selective surface (FSS) with switchable polarization, which is realized using the improved cross slots with embedded strips and isolated island structure. The transmission characteristics of FSS unit cell for both horizontal polarization and vertical polarization are simulated with CST. And a FSS made of an array of 20 X 20 cells is implemented on the substrate Rogers RO4003. The experiment results show that the proposed FSS can obtain polarization switching through short and open circuits for X‐band application. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:515–518, 2014; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.28123. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1729, 2014
1H NMR based metabolic profiling in Crohn's disease by random forest methodology
Authors: Fathi Fariba , Majari‐Kasmaee Laleh , Mani‐Varnosfaderani Ahmad , Kyani Anahita , Rostami‐Nejad Mohammad , Sohrabzadeh Kaveh , Naderi Nosratollah , Zali Mohammad Reza , Rezaei‐Tavirani Mostafa , Tafazzoli Mohsen , Arefi‐Oskouie Afsaneh
Published: April 2014

The present study was designed to search for metabolic biomarkers and their correlation with serum zinc in Crohn's disease patients. Crohn's disease (CD) is a form of inflammatory bowel disease that may affect any part of the gastrointestinal tract and can be difficult to diagnose using the clinical tests. Thus, introduction of a novel diagnostic method would be a major step towards CD treatment.

Proton nuclear magnetic resonance spectroscopy (1H NMR) was employed for metabolic profiling to find out which metabolites in the serum have meaningful significance in the diagnosis of CD. CD and healthy subjects were correctly classified using random forest methodology. The classification model for the external test set showed a 94% correct classification of CD and healthy subjects. The present study suggests Valine and Isoleucine as differentiating metabolites for CD diagnosis. These metabolites can be used for screening of risky samples at the early stages of CD diagnoses.

Moreover, a robust random forest regression model with good prediction outcomes was developed for correlating serum zinc level and metabolite concentrations. The regression model showed the correlation (R2) and root mean square error values of 0.83 and 6.44, respectively. This model suggests valuable clues for understanding the mechanism of zinc deficiency in CD patients. Copyright © 2014 John Wiley & Sons, Ltd.
Electron spin resonance (ESR/EPR) of free radicals observed in human red hair: a new, simple empirical method of determination of pheomelanin/eumelanin ratio in hair
Authors: Chikvaidze Eduard N. , Partskhaladze Tamar M. , Gogoladze Temur V.
Published: April 2014

The definition of the concentration of pheomelanin in the skin is an issue of great interest because in the case of being influenced by UV radiation, it manifests itself as a prooxidant, causing various skin disorders including melanoma that might help to explain the relatively high incidence of skin cancer among individuals with red hair.

The ESR spectra of red hair samples were investigated. It was found that at low microwave power, they are characterized by two types of spectra. Red hair ESR signals result from a superposition of two spectral shapes, a singlet spectrum as a result of the existence of eumelanin and a triplet spectrum as a result of the existence of pheomelanin. At high microwave power, only triplet spectra shape was detected, caused by saturation of the eumelanin singlet. Using different concentration ratios of black to red hair, we measured ESR spectra and plotted the ratio values in each sample against a measured ‘g‐factor’ (experimental). We found that there is a linear relationship between these two parameters. So, it is evident that using these results, the concentration ratio of pheomelanin to eumelanin in a sample of hair can be easily determined by an almost noninvasive method. This can be considered a potential advantage for many practical activities compared with other invasive methods. The concentration dependence curve of pheomelanin (µg/mg) on gexp‐factor in an ESR spectrum of hair has been designed, which allows the determination of the amount of pheomelanin in hair of any color. Copyright © 2014 John Wiley & Sons, Ltd.
Acetone‐induced polymerisation of 3‐aminopropyltrimethoxysilane (APTMS) as revealed by NMR spectroscopy
Authors: Mazzei Pierluigi , Fusco Luigi , Piccolo Alessandro
Published: April 2014

We followed the reactivity of acetone with 3‐aminopropyltrimethoxysilane, a potential organosilane coupling agent, by 1H, 13C and 29Si NMR spectroscopy. Selective 1D and 2D‐edited NMR experiments significantly contributed to simplify the spectral complexity of reaction solution and elucidated molecular structures within progressive reaction phases. The course of the 3‐aminopropyltrimethoxysilane reaction with acetone was shown by a progressive decrease of both reactants, and a concomitant appearance of water and methanol, due to formation of imine and hydrolysis of alkoxysilane groups, respectively. The occurrence of multiple siloxane linkages in a progressively larger cross‐linked macromolecular structure was revealed by DOSY‐NMR experiments and new signals in 29Si‐NMR spectra at different reaction times. The NMR approach described here may be applied to investigate the reactivity of other γ‐aminopropylalkoxysilanes and contribute to define procedures for the preparation of silica‐based materials. Copyright © 2014 John Wiley & Sons, Ltd.
A journey with chronic pain: Self‐directed learning as survival
Authors: King Kathleen P.
Published: April 2014

Over the past 20 years in theUSA, increased insurance control of healthcare decisions, litigation and regulations, have contributed to a dramatic shift in the doctor‐patient relationship and respective responsibilities. This paper presents an autoethnographic study of the self‐directed learning (SDL) strategies and patterns used by an individual navigating the complexities of not only chronic pain, but also healthcare decision making over ten years. The study and discussion examine the experience within the lens ofSDL(Self Directed Learning) and demonstrate its power to transform passive patient behavior to proactive responsibility. This study specifically revealsSDLstrategies used in a chronic pain healthcare journey including, self‐planned learning, inquiry methods, self‐education, self‐instruction, self‐teaching, and self‐study. My travels through urgent and confounding situations were propelled by healthcare processes that failed. The paradigm of self‐directed learning holds promise for mainstream recognition in personal healthcare.
Writing realities: An exploration of drawbacks and benefits of publishing while enrolled in a doctoral program
Authors: Mizzi Robert C.
Published: April 2014

This paper dives into the complicated work of publishing while working on a doctoral dissertation. Although the author recognizes the dissertation as being a capstone synthesis of a multi‐year endeavor, there can be some educational and social benefits to engaging with a publication process. A few key benefits include, but are not limited to, scholarly feedback on ideas, a strengthened writing portfolio and skills, a better position to receive awards, and an expansion of networking opportunities. The author reaffirms existing literature that points out that through publishing work, the doctoral identity shifts from that of being a student to becoming a scholar.
Sigmoidal Maximal Effect Modeling of Low‐Density Lipoprotein Cholesterol Concentration and Annual Incidence of Coronary Heart Disease Events in Secondary Prevention Trials
Authors: Charland Scott L. , Stanek Eric J.
Published: April 2014

Study Objectives

To evaluate the relationship between low‐density lipoprotein cholesterol (LDL‐C) concentration and the annual incidence of combined coronary heart disease (CHD) events—death or nonfatal myocardial infarction (NFMI)—by using sigmoidal maximal effect (sEmax) modeling of published data in various populations at risk for CHD events, and to use the best performing sEmax model generated to calculate the number needed to treat (NNT) to prevent a single CHD death or NFMI event across a range of LDL‐C concentrations.

Design

Literature‐based modeling analysis.

Patients

A total of 95,955 patients from 22 published cardiovascular secondary prevention trials.

Measurements and Main Results

Four distinct sEmax models were created based on intervention approach and CHD event risk for each trial population. Model outputs included the following: Emax (maximum CHD death/NFMI rate), E0 (minimum CHD death/NFMI rate), and fit parameters. The best‐fitting sEmax model was compared with linear, log‐linear, and logit models, and it was used for calculation of annualized NNT to prevent one CHD death or NFMI event with statins. The best fitting sEmax model was constructed from nine statin intervention trials in 60,483 clinically stable patients with CHD or CHD risk equivalents (Emax = 4.84%/year [95% confidence interval (CI) 4.11–5.41%/year], E0 = 1.24%/year [95% CI 0.64–1.83%/year]) and was superior to linear, log‐linear, and logit models. Reduction of CHD death/NFMI incidence diminished at an LDL‐C level near 90 mg/dl and became near static at an LDL‐C level of 60–70 mg/dl. Annual NNT for LDL‐C reduction from a baseline of 130–100 mg/dl, 90, and 70 mg/dl was 129, 104, and 83, respectively, and from a baseline of 100–70 mg/dl was 232.

Conclusion

An sEmax model fully characterized the relationship between LDL‐C concentration and incidence of CHD death or NFMI in a high‐risk population receiving statins, with diminishing event reduction at an LDL‐C level less than 90 mg/dl, and limited projected event reduction beyond an LDL‐C level of ~60–70 mg/dl. As baseline LDL‐C level declines, the NNT sharply increases.
Minimum Qualifications for Clinical Pharmacy Practice Faculty
Authors: American College of Clinical Pharmacy   , Engle Janet P. , Erstad Brian L. , Anderson Douglas C. , Bucklin Mason H. , Chan Alexandre , Donaldson Amy R. , Hagemann Tracy M. , O'Connell Mary Beth , Rodgers Philip T. , Tennant Sarah , Thomas Zachariah
Published: April 2014

The American College of Clinical Pharmacy 2013 Educational Affairs Committee was charged with developing recommendations for the minimum qualifications required for clinical pharmacy practice faculty in United States colleges and schools of pharmacy with respect to education, postgraduate training, board certification, and other experiences. From a review of the literature, the committee recommends that clinical pharmacy practice faculty possess the following minimum qualifications, noting that, for some positions, additional qualifications may be necessary. Clinical pharmacy practice faculty should possess the Doctor of Pharmacy degree from an Accreditation Council for Pharmacy Education–accredited institution. In addition, faculty should have completed a postgraduate year one (PGY1) residency or possess at least 3 years of direct patient care experience. Faculty who practice in identified areas of pharmacotherapy specialization, as identified by American Society of Health‐System Pharmacists postgraduate year two (PGY2) residency guidelines, should have completed aPGY2 residency in that area of specialty practice. Alternatively, faculty should have completed a minimum of aPGY1 residency and 1 additional year of practice, with at least 50% of time spent in their area of specialization, which is documented in a portfolio, or 4 years of direct patient care in their area of specialization, which is documented in a portfolio. Fellowship training or a graduate degree (e.g.,Ph.D.) should be required for research‐intensive clinical faculty positions. All faculty should obtain structured teaching experience during or after postgraduate training, preferably through a formal teaching certificate program or through activities documented in a teaching portfolio. A baseline record of scholarship should be obtained before hire as clinical pharmacy practice faculty through exposure in postgraduate programs or previous employment. Faculty should be board certified before hire or attain board certification within 2 years of hire through the Board of Pharmacy Specialties (BPS) or, if appropriate for the practice area, through a nonBPS‐certifying agency. If no certification exists in the area of specialty, the faculty member should develop a portfolio with evidence of excellence in clinical practice, teaching, and scholarship.
Innovation in Clinical Pharmacy Practice and Opportunities for Academic–Practice Partnership
Authors: American College of Clinical Pharmacy   , Gubbins Paul O. , Micek Scott T. , Badowski Melissa , Cheng Judy , Gallagher Jason , Johnson Samuel G. , Karnes Jason H. , Lyons Kayley , Moore Katherine G. , Strnad Kyle
Published: April 2014

Clinical pharmacy has a rich history of advancing practice through innovation. These innovations helped to mold clinical pharmacy into a patient‐centered discipline recognized for its contributions to improving medication therapy outcomes. However, innovations in clinical pharmacy practice have now waned. In our view, the growth of academic–practice partnerships could reverse this trend and stimulate innovation among the next generation of pioneering clinical pharmacists. Although collaboration facilitates innovation, academic institutions and health care systems/organizations are not taking full advantage of this opportunity. The academic–practice partnership can be optimized by making both partners accountable for the desired outcomes of their collaboration, fostering symbiotic relationships that promote value‐added clinical pharmacy services and emphasizing continuous quality improvement in the delivery of these services. Optimizing academic–practice collaboration on a broader scale requires both partners to adopt a culture that provides for dedicated time to pursue innovation, establishes mechanisms to incubate ideas, recognizes where motivation and vision align, and supports the purpose of the partnership. With appropriate leadership and support, a shift in current professional education and training practices, and a commitment to cultivate future innovators, the academic–practice partnership can develop new and innovative practice advancements that will improve patient outcomes.
Overweight and obesity in patients with cystic fibrosis: A center‐based analysis
Authors: Hanna Reem M. , Weiner Daniel J.
Published: April 2014

Objective

Cystic fibrosis (CF) has long been associated with malnutrition. However, due to early diagnosis, nutritional supplements, and increased prevalence of obesity in the general population, overweight, and obesity in the CF patient population is becoming a concern. The aim of this study was to determine the prevalence of obesity and overweight in patients with CF seen at our center, to analyze factors associated with nutritional status, to evaluate the relation between nutritional status and lung function, and to document any adverse health outcomes.

Methods

The CF Patient Registry was queried for patients aged 2–18 who were seen at our center between June 2011 and June 2012. Nutritional statuses of patients were classified in accordance with the CF Foundation guidelines. Analysis of variance was utilized to analyze the differences in lung function between the five weight status groups.

Results

Of the 226 patients with CF aged 2–18 years, 129 (57%) had a BMI percentile consistent with a healthy weight status, 16 (7%) were in nutritional failure, 28 (12%) were at risk of nutritional failure, 35 (15%) were overweight, and 18 (8%) were obese. Based on fecal elastase levels, 50% of the overweight patients and 20% of the obese patients were pancreatic insufficient. FEV1 % predicted was lowest in patients with nutritional failure (P = 0.005). No significant differences were noted between the other four weight groups. In our obese and overweight population, three patients have impaired glucose tolerance, one has CF‐related diabetes (CFRD) with fasting hyperglycemia, three have hypertension, and one has obstructive sleep apnea (OSA).

Conclusions

The prevalence of overweight and obesity in our CF center is noteworthy, and a significant number of the patients were pancreatic insufficient. In our patient population, overweight, and obesity were not associated with further improvement of lung function. Nutritional approaches need to address the adverse outcomes of overweight and obesity. Pediatr Pulmonol. 2015; 50:35–41. © 2014 Wiley Periodicals, Inc.
Forecasting Scottish Migration in the Context of the 2014 Constitutional Change Debate
Authors: Wiśniowski Arkadiusz , Bijak Jakub , Shang Han Lin
Published: April 2014

Migration to and from Scotland might be affected by the outcome of the 2014 Scottish referendum on the constitutional future of the United Kingdom. This potential change in migration has not been thoroughly analysed to date. The aim of this paper is thus to present a set of predictions of the possible effects of Scottish independence on internal and international migration. In particular, different sources of uncertainty of future migration flows are examined. The presented forecasts are based on the available historical data on migration flows, as well as on the opinions of a panel of experts on future migration trends. Bayesian statistical inference is used to combine different sources of uncertainty in a coherent manner. The results indicate that there is substantial uncertainty about future migration to and from Scotland, which increases with the forecast horizon. The most uncertain flow is international immigration to Scotland. Emigration from Scotland is more likely than not to increase in the near future, whereas migration between Scotland and the rest of the UK is expected to remain at similar levels to the present, irrespective of the outcome of the 2014 independence referendum. © 2014 The Authors. Population, Space and Place Published by John Wiley & Sons Ltd.
Metal‐oxide sites for facile methane dissociation
Authors: Trinchero Adriana , Hellman Anders , Grönbeck Henrik
Published: April 2014

magnified image

Experimental and theoretical studies have lately revealed that under‐coordinated Pd‐sites in the PdO(101) surface act as efficient centers for methane dissociation. Here, the density functional theory is used to explore the underlying reason for the low activation energy by systematically investigating a range of hypothetical metal‐oxides in the PdO structure. Low activation energies are calculated for metal‐oxides where the initial state is stabilized via reduced Pauli repulsion between the methane molecule and the site of dissociation. The low activation energy is found to be an atomic property and facile methane dissociation is predicted for single Pd atoms with appropriate ligands. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transport Properties of Puerarin and Effect of Extract of Radix Angelicae dahuricae on Puerarin Intestinal Absorption Using In Situ and In Vitro Models
Authors: Liao Zheng‐Gen , Liang Xin‐Li , Zhu Jing‐Yun , Zhao Guo‐Wei , Guan Yong‐Mei , Cao Yun‐Chao , Zhao Li‐Jun
Published: April 2014

The root of Angelica dahurica (Radix Angelicae Dahuricae, RAD), which contains coumarins and volatile oil as its main classes of active components, is often given in conjunction with Pueraria root (Radix Puerariae, RP), which contains the phytoestrogen puerarin. The two herbs are considered to be compatible ‘herb‐pairs’ in traditional Chinese medicine. The present investigation investigates the absorption of puerarin from RP and the effect of the total coumarins and volatile oil from RAD on its absorption. The everted gut sac and single‐pass intestinal perfusion methods were used, respectively. The results showed that the absorption of puerarin in the jejunum was significantly increased in the presence of the coumarins and/or volatile oil. The absorption rate constant (Ka) of puerarin increased gradually until the concentration reached 160 µg · mL−1, after which its absorption became saturated and the apparent permeability (Papp) values significantly decreased. The results showed that the intestinal absorption mechanisms of puerarin involved active transportation processes and that puerarin is likely to be a substrate of P‐gp because verapamil significantly affected its Papp and Ka. The absorption of puerarin significantly increased (p < 0.01) when combined with RAD extracts, as shown by the increase in concentration of puerarin in blood from the hepatic portal vein, supporting the concept of RAD and RP as a compatible herb‐pair. Copyright © 2014 John Wiley & Sons, Ltd.
Impact of the model‐building strategy on inference about nonlinear and time‐dependent covariate effects in survival analysis
Authors: Wynant Willy , Abrahamowicz Michal
Published: April 2014

Cox's proportional hazards (PH) model assumes constant‐over‐time covariate effects. Furthermore, most applications assume linear effects of continuous covariates on the logarithm of the hazard. Yet, many prognostic factors have time‐dependent (TD) and/or nonlinear (NL) effects, that is, violate these conventional assumptions. Detection of such complex effects could affect prognosis and clinical decisions. However, assessing the effects of each of the multiple, often correlated, covariates in flexible multivariable analyses is challenging. In simulations, we investigated the impact of the approach used to build the flexible multivariable model on inference about the TD and NL covariate effects. Results demonstrate that the conclusions regarding the statistical significance of the TD/NL effects depend heavily on the strategy used to decide which effects of the other covariates should be adjusted for. Both a failure to adjust for true TD and NL effects of relevant covariates and inclusion of spurious effects of covariates that conform to the PH and linearity assumptions increase the risk of incorrect conclusions regarding other covariates. In this context, iterative backward elimination of nonsignificant NL and TD effects from the multivariable model, which initially includes all these effects, may help discriminate between true and spurious effects. The practical importance of these issues was illustrated in an example that reassessed the predictive ability of selected biomarkers for survival in advanced non‐small‐cell lung cancer. In conclusion, a careful model‐building strategy and flexible modeling of multivariable survival data can yield new insights about predictors’ roles and improve the validity of analyses. Copyright © 2014 John Wiley & Sons, Ltd.
Linear models‐based LPV modelling and control for wind turbines
Authors: Díaz de Corcuera A. , Pujana‐Arrese A. , Ezquerra J. M. , Milo A. , Landaluze J.
Published: April 2014

The non‐linear behaviour of wind turbines demands control strategies that guarantee the robustness of the closed‐loop system. Linear parameter‐varying (LPV) controllers adapt their dynamics to the system operating points, and the robustness of the closed loop is guaranteed in the controller design process. An LPV collective pitch controller has been developed within this work to regulate the generator speed in the above rated power production control zone. The performance of this LPV controller has been compared with two baseline control strategies previously designed, on the basis of classical gain scheduling methods and linear time‐invariant robust H∞ controllers. The synthesis of the LPV controller is based on the solution of a linear matrix inequalities system, proposed in a mixed‐sensitivity control scenario where not only weight functions are used but also an LPV model of the wind turbine is necessary. As a contribution, the LPV model used is derived from a family of linear models extracted from the linearization process of the wind turbine non‐linear model. The offshore wind turbine of 5 MW defined in the Upwind European project is the used reference non‐linear model, and it has been modelled using the GH Bladed 4.0 software package. The designed LPV controller has been validated in GH Bladed, and an exhaustive analysis has been carried out to calculate fatigue load reductions on wind turbine components, as well as to analyse the load mitigation in some extreme cases. Copyright © 2014 John Wiley & Sons, Ltd.
Disclosure of Adverse Events and Errors in Surgical Care: Challenges and Strategies for Improvement
Authors: Lipira Lauren E. , Gallagher Thomas H.
Published: April 2014

The disclosure of adverse events to patients, including those caused by medical errors, is a critical part of patient‐centered healthcare and a fundamental component of patient safety and quality improvement. Disclosure benefits patients, providers, and healthcare institutions. However, the act of disclosure can be difficult for physicians. Surgeons struggle with disclosure in unique ways compared with other specialties, and disclosure in the surgical setting has specific challenges. The frequency of surgical adverse events along with a dysfunctional tort system, the team structure of surgical staff, and obstacles created inadvertently by existing surgical patient safety initiatives may contribute to an environment not conducive to disclosure. Fortunately, there are multiple strategies to address these barriers. Participation in communication and resolution programs, integration of Just Culture principles, surgical team disclosure planning, refinement of informed consent and morbidity and mortality processes, surgery‐specific professional standards, and understanding the complexities of disclosing other clinicians’ errors all have the potential to help surgeons provide patients with complete, satisfactory disclosures. Improvement in the regularity and quality of disclosures after surgical adverse events and errors will be key as the field of patient safety continues to advance.
pH-Dependent accumulation of anticancer compound on mycelia in fermentation of marine fungus
Authors: Zhou Weiqiang , Cai Menghao , Na Ke , Shen Chu , Zhang Xiaoxu , Zhou Xiangshan , Zhao Wenjie , Zhang Yuanxing
Published: April 2014

The real-time distribution of anticancer 1403C in fermentation broth of marine fungus Halorosellinia sp. was investigated. It was closely related with pH variations, which was, 1403C in the supernatant decreased while that in the mycelia increased with pH rising. There was only 0.5 % of the total 1403C left in the supernatant when pH reached 7.0. The scanning electron microscope then provided information that compounds precipitated on the mycelia when pH rose. Then, the pH-regulation experiments proved that 1403C mainly secreted extracellular and easily dissolved in acidic condition but precipitated and absorbed on the mycelia with the increase of broth pH. Thereby, a pH-regulation strategy was proposed and applied to accumulate 1403C on the mycelia before draw-off of fermentation broth. It significantly simplified purification process and is critical for 1403C preparation of industrial scale.
The Evolution of Cancer Risk Assessment in the Era of Next Generation Sequencing
Authors: Fecteau Heather , Vogel Kristen J. , Hanson Kristen , Morrill‐Cornelius Shannon
Published: April 2014

Cancer genetics professionals face a new opportunity and challenge in adapting to the availability of cancer genetic testing panels, now available as a result of Next Generation Sequencing (NGS) technology. While cancer panels have been available for over a year, we believe that there is not yet enough data to create practice guidelines. Despite this, a year of experience allows us to provide our opinion on points to consider as cancer genetic counselors incorporate this testing technology into genetic counseling practice models. NGS technology offers the ability to potentially diagnose hereditary cancer syndromes more efficiently by testing many genes at once for a fraction of what it would cost to test each gene individually. However, there are limitations and additional risks to consider with these tests. Obtaining informed consent for concurrent testing of multiple genes requires that genetics professionals modify their discussions with patients regarding the potential cancer risks and the associated implications to medical management. We propose dividing the genes on each panel into categories that vary by degree of cancer risk (e.g. penetrance of the syndrome) and availability of management guidelines, with the aim to improve patient understanding of the range of information that can come from this testing. The increased risk for identifying variants of uncertain significance (VUS) when testing many genes at once must be discussed with patients. Pretest genetic counseling must also include the possibility to receive unexpected results as well as the potential to receive a result in the absence of related medical management guidelines. It is also important to consider whether a single gene test remains the best testing option for some patients. As panels expand, it is important that documentation reflects exactly which genes have been analyzed for each patient. While this technology holds the promise of more efficient diagnosis for many of our patients, it also comes with new challenges that we must recognize and address.
Comparison of the efficacy of esomeprazole and famotidine against stress ulcers in a neurosurgical intensive care unit
Authors: Lee Tzong‐Hsi , Hung Fang‐Ming , Yang Lin‐Hsue
Published: April 2014

Background

To compare the efficacy of esomeprazole and famotidine against stress ulcers and the association of these prophylactic agents with ventilator‐associated pneumonia in patients admitted to neurosurgical intensive care unit (ICU).

Patients and Methods

Sixty patients were randomly allocated into two groups (the esomeprazole and famotidine groups; n = 30 each) to receive prophylaxis medication for 7 days within 24 hours of admission in a neurosurgical ICU. Patients in the esomeprazole group received esomeprazole (40 mg) dissolved in water once a day through a nasogastric tube, whereas patients in the famotidine group received an intravenous infusion of famotidine (20 mg) every 12 hours. We then compared the occurrence of overt upper gastrointestinal bleeding and ventilator‐associated pneumonia between these two groups.

Results

One patient in the famotidine group had overt upper gastrointestinal bleeding (3.3%), whereas the bleeding was not observed in patients in the esomeprazole group. Ventilator‐associated pneumonia occurred in one patient (3.3%) from each group. One patient died within 30 days (3.3%) in the esomeprazole group and three patients (10%) died in the famotidine group. There was no difference in the occurrence of overt upper gastrointestinal bleeding (p = 1.000), ventilator‐associated pneumonia (p = 1.000), and 30‐day mortality (p = 0.612) between these two groups.

Conclusion

In this small‐scale study, the effect of administration of esomeprazole through a nasogastric tube on stress ulcer was similar to that of intravenous famotidine infusion in neurosurgical ICU patients. In addition, the association between prevalence of ventilator‐associated pneumonia and administration of esomeprazole was also similar to that observed with famotidine infusion.
Empiric antibiotic choices for community‐acquired biliary tract infections
Authors: Chang Kuo‐Kuan , Chang Chin‐Lu , Tai Fang‐Ting , Wang Chun‐Hsiang , Lin Ruey‐Chang
Published: April 2014

Background

The study was conducted to reveal the most appropriate empiric antibiotics for the treatment of community‐acquired biliary tract infections (CA‐BTI) at a regional hospital in Taiwan.

Methods

The study was performed between October 1, 2010 and October 31, 2012. All positive bile culture results of presumptive community‐acquired origins were collected. The associated etiologic microorganisms and their antimicrobial susceptibilities were analyzed. The appropriateness of empiric therapy (defined as the effectiveness of the antibiotics against the etiologic agents) and the subsequent treatment response were examined through the review of medical records.

Results

A total of 115 patients (cholecystitis, 83 cases, 72.2%; cholangitis, 32 cases, 27.8%) and 189 isolates (136 Gram‐negative bacilli, 37 Gram‐positive cocci, and 16 anaerobes) were analyzed. The most frequent pathogens were Escherichia coli (n = 69, 36.5%), Klebsiella spp. (n = 37, 19.6%), enterococci (n = 29, 15.3%), and Bacteroides spp. (n = 11, 5.8%). Penicillin resistance (5.4%) was low in Gram‐positive cocci, whereas higher resistance (>20%) to cefazolin, cefuroxime, and ampicillin–sulbactam was found in Gram‐negative bacilli. Anaerobes also demonstrated high resistance to clindamycin (37.5%) but less to metronidazole (12.5%). Appropriate empiric therapy was found in 92 (80%) cases, and among them, 83 (90.2%) were treated successfully. The treatment success rate (69.6%) was significantly lower among the remaining 23 cases with inappropriate empiric therapy (16 of 23 vs. 83 of 92, p < 0.05). A high treatment success rate (97.2%) was observed among cases empirically treated with ceftriaxone plus metronidazole.

Conclusion

The combination of ceftriaxone plus metronidazole appears to be the most appropriate empiric antibiotics for the treatment of CA‐BTI at this hospital. Because different hospitals may encounter microorganisms of different antimicrobial susceptibilities, similar approaches may be followed by other hospitals where appropriate empiric therapy has not yet been established for the treatment of CA‐BTI.
Thalidomide induces complete remission of advanced hepatocellular carcinoma
Authors: Chien Cheng‐Hung , Chien Rong‐Nan
Published: April 2014

Hepatocellular carcinoma (HCC) is one of the most prevalent human cancers in the world, but its prognosis is extremely poor. HCC is considered a hypervascular tumor. Thalidomide, which has been known to inhibit growth factor‐induced neovascularization, is a convenient alternative to target therapy such as sorafenib. We report a 65‐year‐old male patient with alcoholic liver cirrhosis that was diagnosed having multiple HCCs during surveillance. The patient was assessed as inoperable and unsuited for transhepatic arterial chemoembolization or systemic chemotherapy. After discussing the therapeutic alternatives, he decided to receive low‐dose thalidomide (100 mg daily) therapy. Fortunately, follow‐up liver biochemical tests, serum α‐fetoprotein level, and dynamic computed tomography showed complete remission of the HCCs 4.5 months after thalidomide treatment and this was documented for more than 22 months without evidence of tumor recurrence.
A POSTERIORI RATEMAKING WITH PANEL DATA
Authors: Boucher Jean-Philippe , Inoussa Rofick
Published: April 2014

Ratemaking is one of the most important tasks of non-life actuaries. Usually, the ratemaking process is done in two steps. In the first step, a priori ratemaking, an a priori premium is computed based on the characteristics of the insureds. In the second step, called the a posteriori ratemaking, the past claims experience of each insured is considered to the a priori premium and set the final net premium. In practice, for automobile insurance, this correction is usually done with bonus-malus systems, or variations on them, which offer many advantages. In recent years, insurers have accumulated longitudinal information on their policyholders, and actuaries can now use many years of informations for a single insured. For this kind of data, called panel or longitudinal data, we propose an alternative to the two-step ratemaking approach and argue this old approach should no longer be used. As opposed to a posteriori models of cross-section data, the models proposed in this paper generate premiums based on empirical results rather than inductive probability. We propose a new way to deal with bonus-malus systems when panel data are available. Using car insurance data, a numerical illustration using at-fault and non-at-fault claims of a Canadian insurance company is included to support this discussion. Even if we apply the model for car insurance, as long as another line of business uses past claim experience to set the premiums, we maintain that a similar approach to the model proposed should be used.
Dynamics of iterated function systems on the circle close to rotations
Authors: BARRIENTOS PABLO G. , RAIBEKAS ARTEM
Published: April 2014

We study the dynamics of iterated function systems generated by a pair of circle diffeomorphisms close to rotations in the$C^{1+\text{bv}}$-topology. We characterize the obstruction to minimality and describe the limit set. In particular, there are no invariant minimal Cantor sets, which can be seen as a Denjoy/Duminy type theorem for iterated systems on the circle.
The Archaeological Potential for Reconstructing the History of Labor Relations in East Africa, c. 1500–1900
Authors: Lane Paul J.
Published: April 2014

Previous studies of past labor relations in different parts of Africa have relied almost entirely on documentary sources. While such records can provide valuable insights into the range of different labor categories that have existed and the relative proportions of the population involved, for much of the continent they are severely restricted in a temporal sense. Thus, for many areas suitable documentary materials covering the periods prior to 1850 are scarce; as is the case, for example, for much of East Africa. To extend scholarly understanding of the nature of labor relations prior to this date, alternative sources need to be utilized. This paper presents a brief overview of the potential scope for utilizing archaeological data, with specific reference to mainland Tanzania. The paper also highlights the many limitations of archaeological data and offers some thoughts on how these might be addressed from both a conceptual and methodological perspective. The paper concludes with an appeal for more studies oriented toward investigation of the archaeological remains of the last five hundred years and greater dialogue between the region’s historians and archaeologists.
Studying edge geometry in transiently turbulent shear flows
Authors: Chantry Matthew , Schneider Tobias M.
Published: April 2014

In linearly stable shear flows at moderate Reynolds number, turbulence spontaneously decays despite the existence of a codimension-one manifold, termed the edge, which separates decaying perturbations from those triggering turbulence. We statistically analyse the decay in plane Couette flow, quantify the breaking of self-sustaining feedback loops and demonstrate the existence of a whole continuum of possible decay paths. Drawing parallels with low-dimensional models and monitoring the location of the edge relative to decaying trajectories, we provide evidence that the edge of chaos does not separate state space globally. It is instead wrapped around the turbulence generating structures and not an independent dynamical structure but part of the chaotic saddle. Thereby, decaying trajectories need not cross the edge, but circumnavigate it while unwrapping from the turbulent saddle.
Phoretic self-propulsion at finite Péclet numbers
Authors: Michelin Sébastien , Lauga Eric
Published: April 2014

Phoretic self-propulsion is a unique example of force- and torque-free motion on small scales. The classical framework describing the flow field around a particle swimming by self-diffusiophoresis neglects the advection of the solute field by the flow and assumes that the chemical interaction layer is thin compared to the particle size. In this paper we quantify and characterize the effect of solute advection on the phoretic swimming of a sphere. We first rigorously derive the regime of validity of the thin-interaction-layer assumption at finite values of the Péclet number (${Pe}$). Under this assumption, we solve computationally the flow around Janus phoretic particles and examine the impact of solute advection on propulsion and the flow created by the particle. We demonstrate that although advection always leads to a decrease of the swimming speed and flow stresslet at high values of the Péclet number, an increase can be obtained at intermediate values of${Pe}$. This possible enhancement of swimming depends critically on the nature of the chemical interactions between the solute and the surface. We then derive an asymptotic analysis of the problem at small${Pe}$which allows us to rationalize our computational results. Our computational and theoretical analysis is accompanied by a parallel study of the influence of reactive effects at the surface of the particle (Damköhler number) on swimming.
Geostrophic adjustment with gyroscopic waves: stably neutrally stratified fluid without the traditional approximation
Authors: Reznik G. M.
Published: April 2014

We examine nonlinear geostrophic adjustment in a rapidly rotating (small Rossby number Ro) stably neutrally stratified (SNS) fluid consisting of a stratified upper layer with $N>f$ ($N$ is the buoyancy frequency, $f$ the Coriolis parameter) and a homogeneous lower layer, the density and other fields being continuous at the interface between the layers. The angular speed of rotation is non-parallel to gravity; the traditional and hydrostatic approximations are not used. The wave spectrum in the model consists of internal and gyroscopic waves. During the adjustment an arbitrary long-wave perturbation is split in a unique way into slow quasi-geostrophic (QG) and fast ageostrophic components with typical time scales $(Ro\, f)^{-1}$ and $f^{-1}$, respectively. The QG flow is governed by two coupled nonlinear equations of conservation of QG potential vorticity (PV) in the layers. The fast component is a sum of internal waves and inertial oscillations (long gyroscopic waves) confined to the homogeneous layer and modulated by an amplitude depending on coordinates and slow time. On times $t\sim (\, f\, Ro)^{-1}$ the slow component is not influenced by the fast one but the inertial oscillations amplitude is coupled to the QG flow and obeys an equation practically coinciding with that in the barotropic case (Reznik, J. Fluid Mech., vol. 743, 2014, pp. 585–605). A non-stationary boundary layer with large vertical gradients of horizontal velocity develops in the stratified layer near the interface to prevent penetration of the inertial oscillations into the stratified fluid; an analogous weaker boundary layer arises near the upper rigid lid. At large times the internal waves gradually decay because of dispersion and the resulting motion consists of the slow QG component and inertial oscillations confined to the barotropic lower layer.