bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reflection of plane waves in thermodiffusive elastic half‐space with voids
Authors: Sharma Kunal 
Published: May 2013

PurposeThe present investigation aims to examine the reflection of plane waves from a free surface of a thermodiffusive elastic half space with void.Design/methodology/approachGeneralized theory of thermoelasticity developed by Lord‐Shulma was used to investigate the problem. The amplitude ratios of various reflected waves are obtained in a closed form. The dependence of these amplitude ratios with an angle of propagation as well as other material parameter are shown graphically.FindingsEffects of void and diffusion are observed on these amplitude ratios and have been found to be significant.Originality/valueIt is found that there exist four longitudinal waves (namely P‐wave, thermal wave (T‐wave), mass diffusion wave (MD‐wave), volume fraction wave (VF‐wave, carrying a change in void volume fraction) and a transverse SV wave). Some special cases of interest are also deduced from the present investigation.
Theoretical study of magnetic properties of SrMn1‐xFexO3 perovskites
Authors: Masrour R. , Benyoussef A. , Hamedoun M. 
Published: May 2013

PurposeThis paper aims to combine the results of magnetic measurements with high temperature series expansions to determine the magnetic phase diagram of SrMn1−xFexO3 0≤x≤1 perovskites materials.Design/methodology/approachThe authors have found antiferromagnetic ordering for lightly and heavily Fe‐substituted material, while intermediate substitution leads to spin‐glass behavior. Near the SrMn0.5Fe0.5O3 composition these two types of ordering are found to coexist and affect one another.FindingsThe spin glass behavior may be caused by competing ferromagnetic and antiferromagnetic interactions among Mn4+ and observed Fe3+ and Fe5+ ions.Originality/valueThe magnetic perovskites materials are several application in industrial applications (spintronics, magnetic random‐access memory (MRAM), …).
Reflection and refraction of elastic waves at the interface of an elastic half‐space and initially stressed thermoelastic with voids half‐space
Authors: Kumar Rajneesh , Kumar Rajeev 
Published: May 2013

PurposeThe purpose of this research is to study the reflection and refraction of elastic waves at the interface of an elastic half‐space and initially stressed thermoelastic with voids half‐space.Design/methodology/approachA two‐dimensional model was considered of an isotropic elastic half‐space (medium I) lying over a homogeneous isotropic generalized initially stressed thermoelastic with voids half‐space(medium II). There exist two waves, P‐wave and SV‐wave in isotropic elastic half‐space and three quasi‐longitudinal waves namely, quasi‐longitudinal wave (QP‐mode), quasi‐longitudinal thermal wave (QPT‐mode), quasi‐longitudinal volume fractional wave (QPV‐mode) and one quasi‐transverse wave (QSV‐mode) exists in initially stressed thermoelastic with voids half‐space.FindingsThe energy ratios of these waves are computed along various directions of incident wave, and it is found that the sum of all energy ratios is exactly unity at each value of incident angle. The amplitude ratios of various waves were obtained numerically.Originality/valueReflection and refraction of an elastic medium is of great practical importance. Since valuable organic and inorganic deposits beneath the earth surface are difficult to detect by drilling randomly, wave propagation is the simplest and most economic technique to these and does not require any drilling through the earth. Almost all the oil companies rely on seismic interpretation for selecting the sites for exploratory oil wells because seismic wave methods have higher accuracy, higher resolution and more economical, as compared to drilling which is expansive and time consuming.
It's hard to tell how research feels: using fiction to enhance academic research and writing
Authors: Kara Helen 
Published: May 2013

PurposeThis paper aims to explore the scope of fiction writing in academic research as a way of studying “messier” aspects of the process, such as emotion.Design/methodology/approachThe author reflects on her “lived experience” of conducting doctoral research, five years earlier and re‐searched for the paper, by composing a fictional narrative that aims to capture some of the emotional and other complexities of the process.FindingsThe author demonstrates that fictionalisation opens possibilities for a deeper probing of the emotional aspects of the research experience. Her conclusion is that this method can help researchers to think about the processes of writing, reflexivity, and emotion. It can also be useful to academic writers more widely, by showing how fiction writing techniques can convey some of the more complex aspects of their day‐to‐day activities.Practical implicationsThe paper can act as a model for extending academic writing skills in the area of fiction, by introducing characterisation, plot and dialogue.Originality/valueThis paper offers an original account of the emotions of the doctoral writer, situated within current discourses on emotion, fiction writing and methodology. It will be of value to scholars of arts, humanities and social sciences.
External liberalization by India and China: recent experience and future challenges
Authors: Panagariya Arvind , Sundaram Asha 
Published: May 2013

PurposeIn this study, the authors aim to analyze India's trade performance from the period of liberalization until the recent financial crisis, and compare it to China's.Design/methodology/approachThe authors then examine Indian trade and investment policy and also institutional factors that potentially determine these trade patterns and performance, especially where they differ from China's.FindingsFinally, the authors highlight future trade policy challenges for India and also provide suggestions to ensure strong growth in trade and integration with the global market.Originality/valueThis paper contributes by performing a comparative analysis of the Indian and Chinese experiences under trade liberalization and also by outlining potential challenges for Indian trade policy in the future.
Towards optimal portfolio strategy to control maximum drawdown
Authors: Yang Zhaoji (George) , Zhong Liang 
Published: May 2013

PurposeThe purpose of this paper is to present a discrete quantitative trading strategy to directly control a portfolio's maximum percentage of drawdown losses while trying to maximize the portfolio's long‐term growth rate.Design/methodology/approachThe loss control target is defined through a Rolling Economic Drawdown (REDD) with a constant look‐back time window. The authors specify risk aversion in the power‐law portfolio wealth utility function as the complement of maximum percentage loss limit and assume long‐term stable Sharpe ratios for asset class indexes while updating volatility estimation in dynamic asset allocation implementation.FindingsOver a test period of the past 20 years (1992‐2011), a risk‐based out‐of‐sample dynamic asset allocation among three broad based indexes (equity, fixed income and commodities) and a risk free asset, is robust against variations in capital market expectation inputs, and out‐performs the in‐the‐sample calibrated model and traditional asset allocation significantly.Research limitations/implicationsThe current proposal can lead to a new mathematical framework for portfolio selection. Besides investors' liquidity and behavioural constraints, macroeconomic and market cycle, and the potential of central bank interventions following a market crash, could be additionally considered for a more rigorous dynamic asset allocation model.Practical implicationsBesides the benefit of a clear mandate to construct suitable client portfolios, the portfolio approach can be applied to design invest‐able securities, such as principal‐guaranteed investment products, target risk asset allocation ETFs, and target‐date mutual funds with a glide path, etc. The formulation can also be implemented as a managed futures hedge fund portfolio.Originality/valueThe paper introduces the Rolling Economic Drawdown (REDD) concept and specifies risk aversion as the floor of maximum percentage loss tolerance. Dynamic asset allocation is implemented through updating estimation of asset class volatilities.
Busy boards and corporate performance
Authors: Lu Xianwei , Wang Jianqiong , Dong Dayong 
Published: May 2013

PurposeThe purpose of this paper is to analyze and examine the relationship between busy boards and corporate performance in China.Design/methodology/approachBased on a sample of non‐financial listed companies in the Chinese stock market from 2007 to 2010, by defining several measures of busy board, the paper investigates the relationship between busy boards and corporate performance in China.FindingsThe paper finds many busy boards in Chinese listed companies; compared to companies without multiple directorships, the companies with multiple directorships have better corporate performance; the number of multiple directorships in boards should maintain a certain ratio, or the busy boards will be harmful to the corporate performance.Originality/valueThis is the first paper to analyze and examine the impacts of busy boards on firm performance in China directly. The findings are also useful to regulation of limiting the numbers of independent directors seated on other boards.
Trait‐mediated seed predation, dispersal and survival among frugivore‐dispersed plants in a fragmented subtropical forest, Southwest China
Authors: LAI Xin , GUO Cong , XIAO Zhishu 
Published: May 2013

AbstractBy tracking the fate of individual seeds from 6 frugivore‐dispersed plants with contrasting seed traits in a fragmented subtropical forest in Southwest China, we explored how rodent seed predation and hoarding were influenced by seed traits such as seed size, seed coat hardness and seed profitability. Post‐dispersal seed fates varied significantly among the 6 seed species and 3 patterns were witnessed: large‐seeded species with a hard seed coat (i.e. Choerospoadias axillaries and Diospyros kaki var. silvestris) had more seeds removed, cached and then surviving at caches, and they also had fewer seeds predated but a higher proportion of seeds surviving at the source; medium‐sized species with higher profitability and thinner seed coat (i.e. Phoebe zhennan and Padus braohypoda) were first harvested and had the lowest probability of seeds surviving either at the source or at caches due to higher predation before or after removal; and small‐seeded species with lower profitability (i.e. Elaeocarpus japonicas and Cornus controversa) had the highest probability of seeds surviving at the source but the lowest probability of seeds surviving at caches due to lower predation at the source and lower hoarding at caches. Our study indicates that patterns of seed predation, dispersal and survival among frugivore‐dispersed plants are highly determined by seed traits such as seed size, seed defense and seed profitability due to selective predation and hoarding by seed‐eating rodents. Therefore, trait‐mediated seed predation, dispersal and survival via seed‐eating rodents can largely affect population and community dynamics of frugivore‐dispersed plants in fragmented forests.
Neuropeptide Y Y2R blockade in the central amygdala reduces anxiety‐like behavior but not alcohol drinking in alcohol‐dependent rats
Authors: Kallupi Marsida , Vendruscolo Leandro F. , Carmichael Casey Y. , George Olivier , Koob George F. , Gilpin Nicholas W. 
Published: May 2013

AbstractElectrophysiological data suggest a dual role of Y2 receptors (Y2Rs) as autoreceptors regulating neuropeptide Y release and heteroceptors regulating gamma‐aminobutyric acid release in the central amygdala (CeA). Here, we report that neither systemic (JNJ‐31020028) nor intra‐CeA (BIIE0246) Y2R antagonism altered operant alcohol responding by alcohol‐dependent or non‐dependent rats. Conversely, BIIE0246 in the CeA reduced anxiety‐like behavior in alcohol‐dependent and alcohol‐naïve rats. The finding that Y2R antagonism reduces anxiety‐like behavior but not alcohol drinking suggests that these two effects may occur via different functions of the Y2R (e.g. autoreceptor versus heteroceptor function).
The absence of fire can cause a lag phase: The invasion dynamics ofBanksia ericifolia(Proteaceae)
Authors: Geerts Sjirk , Moodley Desika , Gaertner Mirijam , Le Roux Johannes J. , McGeoch Melodie A. , Muofhe Cedric , Richardson David M. , Wilson John R. U. 
Published: May 2013

AbstractThe transition from a species introduction to an invasion often spans many decades (a lag phase). However, few studies have determined the mechanisms underlying lag phases. Such a mechanistic understanding is vital if the potential ecosystem‐level impacts are to be predicted and the invasion risks to be managed proactively. Here we examineBanksia ericifolia, introduced for floriculture toSouthAfrica, as a case study. We found 18 sites where the species has been planted, with self‐sustaining (naturalized) populations at four sites, and an invasive population at one site. The invasion originated from around 100 individuals planted 35 years ago; after several fires this population has grown to approximately 10 000 plants covering about 127 ha. The current invasion ofB. ericifoliaalready has ecosystem‐level impacts, for example the nectar available to bird pollinators has more than doubled, potentially disrupting native pollination networks. If fires occurred at the other naturalized sites we anticipate populations would rapidly spread and densify with invaded areas ultimately become banksia‐dominated woodlands. Indeed the only site other than the invasive site where fire has occurred regularly is already showing signs of rapid population growth and spread. However, recruitment is mainly immediately post fire and no seed bank accumulates in the soil, mechanical control of adult plants is cheap and effective, and immature plants are easily detected. This study is a first in illustrating the importance of fire in driving lag phases and provides a valuable example for why it is essential to determine the mechanisms that mediate lag phases in introduced plant species. Serotinous species that have been introduced to areas where fire is suppressed could easily be misinterpreted as low risk species whilst they remain in a lag phase, but they can represent a major invasion risk.
Potential Prevention of Pacing‐Induced Heart Failure Using Simple Pacemaker Programming Algorithm
Authors: Chwyczko Tomasz , Dąbrowski Rafał , Maciąg Aleksander , Sterliński Maciej , Smolis‐Bąk Edyta , Borowiec Anna , Kowalik Ilona , Łabęcka Andrada , Jankowska Agnieszka , Kośmicki Marek , Janas Jadwiga , Pytkowski Mariusz , Szwed Hanna 
Published: May 2013

IntroductionRight ventricular pacing (RVP) causes ventricular desynchronization and may lead to the development of heart failure (HF). Prolongation of atrioventricular delay (AVD) in DDDR pacemakers reduces unnecessary RV stimulation. The aim of the study was to verify the influence of RVP reduction on HF symptoms.MethodsThe study comprised 31 patients (17 men, mean age: 71.6 ± 8 yrs) with DDDR pacemaker implanted due to sinus node dysfunction (SND). At baseline, 28 patients did not present any symptoms of HF. Three patients were in NYHA class II. Patients were randomized either to 150 ms AVD or to minimizing right ventricular pacing (MRVP). Crossing over to the alternate mode took place after 4 months. Cardiopulmonary exercise test (CPX), echocardiography (ECHO) and BNP measurements were done before pacemaker implantation, after 4 and 8 months.ResultsThe percentage of RVP was significantly higher in 150 ms AVD than in MRVP: 81.7 ± 22.6 versus 14.2±20.5%, P < 0.0001. Patients with 150 ms mode had worse CPX parameters than those with MRVP mode: peak oxygen uptake was 14.2±4.3 versus 19.9±6.3 ml/kg per min, P = 0.0001, higher BNP concentrations: 72.3±48.3 versus 49.4±43.9 pg/ml, P = 0.001 and worse left ventricle [LV] function: ejection fraction: 53.2±6.7 versus 57.3±5.5%, P < 0.0001; LV diastolic diameter: 4.86±0.52 versus 4.66±0.5 cm, P < 0.01.ConclusionPredominant RVP in patients without symptoms of HF at baseline may be responsible for worse performance in cardiopulmonary exercise test, higher BNP concentrations and impairment of LV function. Specific DDDR pacemaker programming promotes intrinsic AV conduction and may prevent the development of pacing‐induced HF.
Electrocardiographic Abnormalities and Elevated cTNT at Admission for Intracerebral Hemorrhage: Predictors for Survival?
Authors: Hjalmarsson Clara , Bergfeldt Lennart , Bokemark Lena , Manhem Karin , Andersson Björn 
Published: May 2013

BackgroundCerebrovascular lesions are often associated with electrocardiographic (ECG) abnormalities. The main purpose of this work was to investigate the prognostic value of ECG abnormalities and/or elevated cardiac troponin (cTNT) on admission in patients with nontraumatic intracerebral hemorrhage (ICH).MethodsNinety‐seven consecutive patients with ICH were included. The predictive value of ECG abnormalities and increased TNT on survival were evaluated using Cox proportional hazard model.ResultsThe most frequently observed ECG abnormalities were the presence of a Q wave (39.6%), followed by prolonged QTc (>0.44 s; 35.4%), which was an independent predictor for long‐term mortality (P = 0.019). No difference in QTc was observed between patients with right versus left ICH. Increased cTNT levels at admission had no prognostic value.ConclusionVarious ECG changes were common in patients presenting with an ICH, but only prolonged QTc was found to be an independent predictor of poor survival during follow‐up after ICH.
Clinical decision making: how surgeons do it
Authors: Crebbin Wendy , Beasley Spencer W. , Watters David A. K. 
Published: May 2013

AbstractClinical decision making is a core competency of surgical practice. It involves two distinct types of mental process best considered as the ends of a continuum, ranging from intuitive and subconscious to analytical and conscious. In practice, individual decisions are usually reached by a combination of each, according to the complexity of the situation and the experience/expertise of the surgeon. An expert moves effortlessly along this continuum, according to need, able to apply learned rules or algorithms to specific presentations, choosing these as a result of either pattern recognition or analytical thinking. The expert recognizes and responds quickly to any mismatch between what is observed and what was expected, coping with gaps in information and making decisions even where critical data may be uncertain or unknown. Even for experts, the cognitive processes involved are difficult to articulate as they tend to be very complex. However, if surgeons are to assist trainees in developing their decision‐making skills, the processes need to be identified and defined, and the competency needs to be measurable. This paper examines the processes of clinical decision making in three contexts: making a decision about how to manage a patient; preparing for an operative procedure; and reviewing progress during an operative procedure. The models represented here are an exploration of the complexity of the processes, designed to assist surgeons understand how expert clinical decision making occurs and to highlight the challenge of teaching these skills to surgical trainees.
Empirical Likelihood for Nonparametric Models Under Linear Process Errors
Authors: Qin Yongsong , Lei Qingzhu , Luo Lijun 
Published: May 2013

SummaryIn this paper, we study the construction of confidence intervals for a nonparametric regression function under linear process errors by using the blockwise technique. It is shown that the blockwise empirical likelihood (EL) ratio statistic is asymptoticallydistributed. The result is used to obtain EL based confidence intervals for the nonparametric regression function. The finite‐sample performance of the method is evaluated through a simulation study.
Exercise Studies in Patients With Rotary Blood Pumps: Cause, Effects, and Implications for Starling‐Like Control of Changes in Pump Flow
Authors: Salamonsen Robert F. , Pellegrino Vincent , Fraser John F. , Hayes Kate , Timms Daniel , Lovell Nigel Hamilton , Hayward Christopher 
Published: May 2013

AbstractThis multicenter study examines in detail the spontaneous increase in pump flow at fixed speed that occurs in exercise. Eight patients implanted with the VentrAssist rotary blood pump were subjected to maximal and submaximal cycle ergometry studies, the latter being completed with patients supine and monitored with right heart catheter and echocardiography. Maximal exercise studies conducted in each patient at three different pump speeds on separate days established initially the magnitude and consistency of increases in pump flow that correlated well with changes in heart rate. However, there was considerable variation, coefficients of variation for mean heart rate and pump flow being 47.9 and 49.3%, respectively. Secondly, these studies indicated that increasing pump flows caused significant improvements in maximal exercise capacity. An increase of 2.1 L/min (35%) in maximum blood flow caused 12 W (16%) further increase in achievable work, 1.26 (9.3%) mL/kg/min in maximal oxygen uptake, and 2.3 (23%) mL/kg/min in anaerobic threshold. Mean increases in lactate were 0.85 mm (24%), but mean B‐type natiuretic peptide fell by 126 mm, (−78%). From submaximal supine exercise studies, multiple linear regression of pump flow on factors thought to underlie the spontaneous increase in pump flow indicated that it was associated with increases in heart rate (P = 0.039), pressure gradient across the left ventricle (P = 0.032), and right atrial pressure (P = 0.003). These changes have implications for the recently reported Starling‐like controller for pump flow based on pump pulsatility values, which emulates the Starling curve relating pump output to left ventricular preload. Unmodified, the controller would not permit the full benefits of this effect to be afforded to patients implanted with rotary blood pumps. A modification to the pump control algorithm is proposed to eliminate this problem
Review article: prescribing medications in patients with cirrhosis – a practical guide
Authors: Lewis J. H. , Stine J. G. 
Published: May 2013

SummaryBackgroundMost drugs have not been well studied in cirrhosis; recommendations on safe use are based largely on experience and/or expert opinion, with dosing recommendations often based on pharmacokinetic (PK) changes.AimTo provide a practical approach to prescribing medications for cirrhotic patients.MethodsAn indexed MEDLINE search was conducted using keywords cirrhosis, drug‐induced liver injury, pharmacodynamics (PDs), PKs, drug disposition and adverse drug reactions. Unpublished information from the Food and Drug Administration and industry was also reviewed.ResultsMost medications have not been adequately studied in cirrhosis, and specific prescribing information is often lacking. Lower doses are generally recommended based on PK changes, but data are limited in terms of correlating PD effects with the degree of liver impairment. Very few drugs have been documented to have their hepatotoxicity potential enhanced by cirrhosis; most of these involve antituberculosis or antiretroviral agents used for HIV or viral hepatitis. Paracetamol can be used safely when prescribed in relatively small doses (2–3 g or less/day) for short durations, and is recommended as first‐line treatment of pain. In contrast, NSAIDs should be used cautiously (or not at all) in advanced cirrhosis. Proton pump inhibitors have been linked to an increased risk of spontaneous bacterial peritonitis (SBP) in cirrhosis and should be used with care.ConclusionsMost drugs can be used safely in cirrhosis, including those that are potentially hepatotoxic, but lower doses or reduced dosing frequency is often recommended, due to altered PKs. Drugs that can precipitate renal failure, gastrointestinal bleeding, SBP and encephalopathy should be identified and avoided.