bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Trimetazidine in Angina Pectoris by Echocardiography and Radionuclide Angiography: A Meta‐Analysis of Randomized, Controlled Trials
Authors: Hu Bo , Li Wei , Xu Tao , Chen Tao , Guo Jin
Published: April 2011

Background:

The objective of this meta‐analysis was to evaluate the efficacy of the metabolic agent trimetazidine (TMZ) as monotherapy in the treatment of stable angina pectoris, from echocardiography and radionuclide angiography data.

Hypothesis:

Treatment with TMZ proved to be as effective as other first‐line antianginal agents for coronary patients, and it provided additional efficacy in combination with hemodynamic agents.

Methods:

A search of the literature published between 1965 and 2008 was performed on the MEDLINE and EMBASE databases. Only randomized, controlled trials were included in this meta‐analysis. Patients had to be treated for at least 2 weeks with data on the following 4 parameters at baseline and at the end of the treatment period: left ventricular ejection fraction (LVEF), LV end‐diastolic volume (LVEDV), LV end‐systolic volume (LVESV), and wall motion score index (WMSI). The quality of the trials was assessed by the Jadad score.

Results:

Eleven clinical studies meeting our criteria were analyzed. Results showed that TMZ significantly improved LVEF, with a mean increase of 6.88% (95% confidence interval [CI]: 5.50–8.25), and significantly reduced LVESV by 11.58 mL (95% CI: 5.79–17.37) and WMSI by 0.23 (95% CI: 0.07–0.38). Changes in LVEDV were variable. In both the long term and the short term, TMZ can improve LV function. The efficacy was unchanged in patients with diabetes mellitus.

Conclusions:

This meta‐analysis confirmed the efficacy of TMZ monotherapy in improving LV function compared with placebo. © 2011 Wiley Periodicals, Inc.

The authors have no funding, financial relationships, or conflicts of interest to disclose.
Aortic and Coronary Artery Dissection During Percutaneous Coronary Intervention: A Case Report and Review Article
Authors: Yarlioglues Mikail , Tasdemir Kutay , Kaya Mehmet Gungor , Kalay Nihat
Published: April 2011

Coronary artery dissection is an uncommon but potentially serious complication in percutaneous coronary interventions. We treated a 53‐year‐old female patient with right coronary spasm, which was misdiagnosed as a coronary lesion. The coronary spasm resolved with nitrate administration, but proximal coronary dissection developed during angiography. It progressed anterograde and led to inferior myocardial infarction and severe hemodynamic instability due to right coronary artery occlusion. Percutaneous intervention failed, and it was determined that coronary dissection progressed retrograde, across the truncus of the aorta. Ascending aortic grafting and coronary bypass surgery were performed. The patient recovered and was discharged after 10 days. Close cardiothoracic observation is mandatory in patient evaluation and management. © 2011 Wiley Periodicals, Inc.

The authors have no funding, financial relationships, or conflicts of interest to disclose.
Assessment of Systolic and Diastolic Function in Asymptomatic Subjects Using Ambulatory Monitoring With Acoustic Cardiography
Authors: Dillier Roger , Zuber Michel , Arand Patricia , Erne Susanne , Erne Paul
Published: April 2011

Background:

Adequately recording diastolic heart sounds and systolic time intervals over longer periods is difficult. Thus, information on the circadian variation of these parameters in an ambulatory population is lacking. Moreover, age‐related changes in the prevalence of diastolic heart sounds and measurements of systolic time intervals in an asymptomatic population have not been studied in continuous recordings.

Hypothesis:

Diastolic heart sounds and systolic time intervals will have age and circadian variations that reflect known changes in cardiac function due to aging and circadian rhythms.

Methods:

We studied 128 asymptomatic subjects wearing an ambulatory monitor with acoustic cardiography. The recording spanned a mean duration of 14 hours, including sleep. Data were analyzed for the presence of third (S3) and fourth (S4) heart sounds and for systolic time intervals.

Results:

In these asymptomatic subjects, S3 was significantly more prevalent in those age <40 years than in those age >40 years, and significantly more pronounced during sleep in the younger group. Also, S4 was significantly more prevalent in those age >40 years and significantly more pronounced during sleep in those age >40 years. In contrast, time intervals reflecting systolic function showed less circadian variation and less worsening with age.

Conclusions:

The nocturnal increase of S4 in the elderly reflects diastolic impairment—likely a result of changes in diastolic filling patterns with increasing age. An S3 after the age of 40 is a relatively uncommon finding and therefore should be a specific sign of cardiac disease. Continuous monitoring of diastolic heart sounds and systolic time intervals is possible using acoustic cardiography. © 2011 Wiley Periodicals, Inc.

Patricia Arand, PhD, is an employee of Inovise Medical. The authors have no other funding, financial relationships, or conflicts of interest to disclose.
Insulin Resistance, Inflammation, and Vascular Disease in Nondiabetic Predialysis Chronic Kidney Disease Patients
Authors: Banerjee Debasish , Recio‐Mayoral Alejandro , Chitalia Nihil , Kaski Juan‐Carlos
Published: April 2011

Background:

Chronic kidney disease (CKD) is associated with high cardiovascular morbidity and mortality, which is not fully explained by traditional risk factors; hence, the interest in nontraditional risk factors such as inflammation and insulin resistance (IR). Though IR is shown in nondiabetic CKD, its association with vascular disease and inflammation in this population is unknown, and is what this study aims to investigate.

Hypothesis:

IR and inflammation are related to vascular disease in nondiabetic predialysis CKD patients.

Methods:

We studied carotid‐artery intima‐media thickness (IMT) and endothelial function (brachial artery flow mediated dilation [FMD]) in 35 nondiabetic predialysis patients with stage 3–5 CKD and 35 age‐ and gender‐matched controls. Insulin resistance was measured using the homeostasis model assessment for insulin resistance score (HOMA‐IR), inflammation by high‐sensitivity CRP (hsCRP), and their relationship with FMD and IMT.

Results:

Patients with CKD showed reduced FMD (3.34 ± 2.14% vs 5.27 ± 1.78%, P<0.001) and increased IMT (0.78 ± 0.22 mm vs 0.64 ± 0.16 mm, P = 0.003) compared with controls. The CKD patients had a higher HOMA‐IR (2.20 ± 1.08 vs 1.13 ± 0.64, P<0.001) and hsCRP (3.25 ± 5.47 mg/L vs 1.10 ± 1.85 mg/L [median ± interquartile range], P = 0.02). In the study population, HOMA‐IR was directly related to hsCRP. After adjusting for traditional risk factors, high HOMA‐IR and hsCRP were significantly related to decreased FMD (adjusted β = − 0.44, 95% confidence interval [CI]: − 1.55 to − 0.08, P = 0.003 and adjusted β = − 0.51, 95% CI: − 0.51 to − 0.15, P = 0.001) and increased IMT (adjusted β = 0.62, 95% CI: 0.54–1.90, P = 0.001 and adjusted β = 0.43, 95% CI: 0.08–0.57, P = 0.011), respectively.

Conclusions:

Subjects with systemic inflammation were more insulin‐resistant, and in nondiabetic predialysis CKD, IR and systemic inflammation were independently associated with endothelial dysfunction and atherosclerosis. © 2011 Wiley Periodicals, Inc.

Dr. Debasish Banerjee and Dr. Alejandro Recio‐Mayoral are joint first authors. This study has been supported by grants awarded by the Spanish Society of Cardiology to Dr. A. Recio‐Mayoral and by the St. George's Charitable Foundation to Dr. D. Banerjee. The authors have no other funding, financial relationships, or conflicts of interest to disclose.
Repeat Percutaneous Balloon Mitral Valvotomy vs Mitral Valve Replacement in Patients With Restenosis After Previous Balloon Mitral Valvotomy and Unfavorable Valve Characteristics
Authors: Aslanabadi Naser , Golmohammadi Ali , Sohrabi Bahram , Kazemi Babak
Published: April 2011

Background:

Symptomatic mitral restenosis develops in up to 21% of patients after percutaneous balloon mitral valvotomy (PBMV), and most of these patients undergo mitral valve replacement (MVR).

Hypothesis:

Repeating PBMV (re‐PBMV) might be an effective and less‐invasive treatment for these patients.

Methods:

Forty‐seven patients with post‐PBMV mitral restenosis and unfavorable valve characteristics were assigned either to re‐PBMV (25 cases; mean age 40.7 ± 11 y, 76% female) or MVR (22 cases; mean age 47 ± 10 y, 69% female) at 51 ± 33 months after the prior PBMV. The mean follow‐up was 41 ± 32 months and 63 ± 30 months for the re‐PBMV and MVR groups, respectively.

Results:

The 2 groups were homogenous in preoperative variables such as gender, echocardiographic findings, and valve characteristics. Patients in the MVR group were older, with a higher mean New York Heart Association functional class, mean mitral valve area, mitral regurgitation grade, and right ventricular systolic pressure (P = 0.03), and more commonly were in AF. There were 3 in‐hospital deaths (all in the MVR group) and 4 during follow‐up (3 in the MVR group and 1 in the re‐PBMV group). Ten‐year survival was significantly higher in re‐PBMV vs MVR (96% vs 72.7%, P<0.05), but event‐free survival was similar (52% vs 50%, P = 1.0) due to high reintervention in the re‐PBMV group (48% vs 18.1%, P = 0.02).

Conclusions:

In a population with predominantly unfavorable characteristics for PBMV, short‐ and long‐term outcomes are both reasonable after re‐PBMV with less mortality but requiring more reinterventions compared with MVR. © 2011 Wiley Periodicals, Inc.

The authors have no funding, financial relationships, or conflicts of interest to disclose.
Melphalan‐Induced Supraventricular Tachycardia: Incidence and Risk Factors
Authors: Feliz Victor , Saiyad Saleem , Ramarao Sumana M. , Khan Hammad , Leonelli Fabio , Guglin Maya
Published: April 2011

Background:

Cardiotoxicity of aggressive chemotherapeutic regimens includes cardiomyopathy and arrhythmias. Although cardiomyopathy is a well‐recognized entity, arrhythmias are poorly studied.

Hypothesis:

Certain chemotherapeutic regimes are associated with supraventricular arrhythmias, particularly atrial fibrillation.

Methods:

We retrospectively reviewed the data on patients who received hematopoietic stem cell transplant (bone marrow transplant; BMT) from 1998 to 2005 and developed supraventricular tachycardia (SVT) during the same hospital admission. The Fisher χ2 test and the Student t test were used for comparison of categorical and continuous variables, respectively.

Results:

During the period of 1998–2005, there were 1221 BMTs, 62 (5.1%) of which were complicated by SVT. Melphalan‐based regimens demonstrated a significantly higher rate of SVT than any other chemotherapy. Out of 438 patients who received melphalan, 48 (11%) developed atrial fibrillation (n = 35) or SVT (n = 13) during the same hospital admission, and 390 did not. Patients with SVT were older, had higher baseline creatinine, larger size of the left atrium, and more cardiac comorbidities. Incidence of SVT was associated with greater length of stay (24.9 ± 8.9 d vs 19.6 ± 5.8 days, P<0.0001), even after adjustment for comorbidities.

Conclusions:

Supraventricular tachycardia, mostly atrial fibrillation, complicates about 5% of chemotherapeutic treatments used with BMT. Melphalan is the most arrhythmogenic agent, and is associated with SVT in 11% of patients. Development of SVT results in about a 4‐day increase in the length of hospital stay. © 2011 Wiley Periodicals, Inc.

The authors have no funding, financial relationships, or conflicts of interest to disclose.
An Environmental Threshold of Soil Test P and Degree of P Saturation of Brazilian Oxisols
Authors: Ghosh Amlan Kumar , Barbosa Joyce , da Silva Ivo Ribeiro
Published: April 2011

To develop P management guidelines for poultry litter application in Oxisols of Brazil, the relationship between water soluble P (WSP), soil test P (STP), and degree of P saturation (DPS) needs to be established. The study examined this relationship in Oxisols of Brazil receiving poultry litter. Soils were analyzed for Mehlich‐1 P (M1‐P), WSP, P fractions, P sorption index (PSI), and P saturation based on Mehlich‐1 extractable P, Al, Fe (DPSM1), and PSI (DPSPSI). Surface water bodies in the catchment area were examined for inorganic and total P. All the surface water bodies in the catchment area of the sampled plots were highly enriched in inorganic and organic P. Enrichment of soil P fractions following poultry litter application followed the order HCl‐bound > NaOH‐bound > NaHCO3‐bound fraction. M1‐P was correlated to labile (NaHCO3‐Pi), and stable P pools (NaOH‐P and HCl‐P) and reflected the cumulative P accumulation in these soils. P saturation indices increased with cumulative P addition and increasing M1‐P. WSP increased with increasing DPS and a change point was noticed at 23% DPSPSI (equivalent to DPSM1 of 16.5%) corresponding to M1‐P of 44.5 mg P kg−1, which could be regarded as threshold for P loss in these soils.
Theoretical and Experimental Studies on the Mechanism of Coloration of Polyimides
Authors: Abe Atsutoshi , Nakano Takashi , Yamashita Wataru , Fukukawa Kenichi , Okazaki Masaki , Tamai Shoji
Published: April 2011

The mechanism of coloration of polyimides is investigated theoretically and experimentally. Since light is considered to be absorbed by polyimides via charge‐transfer excitation, we used the long‐range‐corrected time‐dependent density functional theory recently developed by Tawada et al. [Y. Tawada, T. Tsuneda, S. Yanagisawa, T. Yanai, K. Hirao J. Chem. Phys. 2004, 120, 8425] for the calculation of excitation energies and oscillator strengths. Classical molecular dynamic simulations for packed chain models of polyimides were also performed to analyze the structural information of polyimides in condensed phase. In order to predict the transparency of polyimide film, we developed a theoretical method by combining the results of electronic structure calculations and those of molecular dynamics simulations. We compare our theoretical results with experimental ones and discuss the difference between them. As a result, we clarify the new mechanism of coloration and obtain results for the theoretical UV/Visible spectra.
Inelastic Neutron Scattering Study of PtII Complexes Displaying Anticancer Properties
Authors: Batista de Carvalho Luís A. E. , Marques M. Paula M. , Martin Christine , Parker Stewart F. , Tomkinson John
Published: April 2011

The well‐known platinum(II) chemotherapeutic drugs cisplatin [cis‐(NH3)2PtCl2] and carboplatin [Pt(NH3)2C6O4H6], as well as the analogous transplatin [trans‐(NH3)2PtCl2], were studied by inelastic neutron scattering (INS) spectroscopy, coupled to quantum mechanical methods, and some ancillary work with X‐ray diffraction on powders. An assignment of the experimental spectra was carried out based on the calculated INS transition frequencies and intensities (at the DFT level), thereby achieving a good correspondence between the calculated and observed data. Unusually good‐quality INS spectra were obtained from about 250 mg, which is the smallest sample of a hydrogenous compound for which a successful INS interpretation has been reported. The knowledge of the local configuration of this kind of complexes is essential for an accurate understanding of their activity, which will pave the way for the rational design of novel third‐generation drugs comprising cisplatin‐ and carboplatin‐like moieties.
Sustainable Development in the Russia Federation: The Limits of Greening within Industrial Firms
Authors: Crotty Jo , Rodgers Peter
Published: April 2011

The extant literature states that firms ‘go green’ in response to one or a combination of three factors: regulation, stakeholder pressure or ‘because it pays’, with each being tempered by managerial attitudes and perceptions. In this paper, we test the relevance of these factors in the empirical setting of Russia. Data collected from firms in three industrialised regions indicates that Russia's ‘coercive’ approach to regulatory enforcement has resulted in firms seeking to limit their environmental punishment, rather than improve their environmental management. Similarly, weak civil society in Russia has meant that stakeholders such as environmental non‐governmental organisations fail to influence greening activity. We find that only ‘because it pays’ motives were persuasive. The paper concludes that, in settings such as the Russian Federation, market mechanisms are the only method by which to facilitate corporate greening and that steps should be taken to strengthen instruments like ISO 14001 to facilitate greening of this type. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment.
A framework for fiber delay‐line buffers in packet‐based asynchronous multifiber optical networks (PAMFONET)
Authors: Zhang Tao
Published: April 2011

A major challenge in packet‐based optical networks is packet contention, which occurs when two or more packets are heading to the same output at the same time. To resolve contention in the optical domain, a fundamental approach is fiber delay‐line (FDL) buffering, in which packets can be delayed for a fixed amount of time. In the literature, the performance of FDL buffering has been studied extensively. However, most existing works are based on an assumption that there is only one fiber per link in the network. In this paper, we address the architecture and performance of FDL buffers in packet‐based asynchronous multifiber optical networks (PAMFONET), in which each link in the network may consist of multiple optical fibers. We propose a framework for FDL buffers in PAMFONET, in which we provide three essential architectures and corresponding packet scheduling policies. Extensive simulation results show that, with appropriate settings, the same number of FDLs can lead to better performance in multifiber networks than in single‐fiber networks. Copyright © 2011 John Wiley & Sons, Ltd.
High‐fat diet protects BB/OK rats from developing type 1 diabetes
Authors: Bahr Jeanette , Klöting Nora , Wilke Barbara , Klöting Ingrid , Follak Niels
Published: April 2011

Background

It is well known that lipid metabolism plays an important role in the early stages of type 1 diabetes (T1D). For that reason, we examined factors that influence lipid metabolism of BioBreeding/Ottawa Kalsburg (BB/OK) rats that spontaneously develop an insulin‐dependent T1D.

Methods

BB/OK female rats were fed a high‐fat diet during pregnancy (Ssniff R–Z + 10% tallow) and their progeny were also given this diet up to an age of 30 weeks (n = 55) or 4 weeks (n = 14) to study gene expression of Pparg, Fasn, Lep, Adipoq, Repin1, Rarres 2, and Glut4 in adipose tissue. Forty‐two BB/OK rats fed the normal diet (Ssniff R–Z) during pregnancy and the observation period served as controls.

Results

The high‐fat diet significantly decreased diabetes frequency in BB/OK rats when compared with control rats (71 versus 95%, p = 0.002). Although this difference was also reflected in the male rats (68 versus 100%, p = 0.003), no significant variation was observed in female rats (73 versus 90%, p = 0.23). The high‐fat diet resulted in significantly reduced mRNA expression of examined genes in subcutaneous adipose tissue, but not in visceral adipose tissue, except for Fasn and Repin1 expression.

Conclusions

A high‐fat diet seems to protect BB/OK rats from T1D in a sex‐specific manner. The data suggest that a high‐fat diet might influence fat accumulation and/or fat metabolism and prevent T1D development in male rats, which is supported by changes in adipose tissue gene expression. Copyright © 2011 John Wiley & Sons, Ltd.
Bis(diethylamino)(pentafluorophenyl)phosphane – a Push–Pull Phosphane Available for Coordination
Authors: Orthaber Andreas , Fuchs Michael , Belaj Ferdinand , Rechberger Gerald N. , Kappe C. Oliver , Pietschnig Rudolf
Published: April 2011

A facile large‐scale synthesis of the “push–pull”‐substituted ligand bis(diethylamino)(pentafluorophenyl)phosphane is reported. A selenophosphorane as well as complexes with CuI and PdCl2, can be formed almost quantitatively from suitable starting materials. The PdII complex shows a square‐planar coordination with significant distortions of the Cl–Pd–Cl moiety in the solid state. In contrast, the phosphane ligand exhibits a large flexibility in the trigonal‐planar coordination of the Cu salt, as proven by X‐ray crystallography. C–C cross‐coupling reactions and 1,3‐dipolar cycloadditions have been tested for the PdII and CuI complexes, respectively. Whereas the reactivity of the PdII complex is good at low temperature, the CuI complex reveals remarkable reaction rates at temperatures up to 130 °C. Furthermore, the CuI‐catalyzed azide/alkyne 1,3‐dipolar cycloaddition was successfully adapted for flow conditions.
Electrophoretic and zymographic characterization of proteins isolated by various extraction methods from ejaculated and capacitated boar sperms
Authors: Zigo Michal , Jonáková Věra , Maňásková‐Postlerová Pavla
Published: April 2011

The presented work focuses on electrophoretic and zymographic characterization of boar sperm proteins isolated by various extraction methods and on comparison of the protein profiles obtained from ejaculated and in vitro capacitated spermatozoa. Sperm proteins of ejaculated and in vitro capacitated boar sperms were isolated with the following agents: 1% v/v Triton X‐100, 1% v/v Triton X‐114, 2% v/v acetic acid, 1% m/v sodium dodecyl sulphate (SDS), 30 mM N‐octyl‐β‐D‐glucopyranoside (OBG), rehydration buffer (RHB) for isoelectric focusing and finally by the freezing–thawing approach. The extracts were characterized in terms of 1‐DE, 2‐DE protein profiles, 1‐DE glycoprotein staining and proteinase and hyaluronidase substrate zymographic profiles. The results have shown quantitative and qualitative differences in 1‐DE protein and glycoprotein profiles with respect to the employed isolation approach. These differences were seen even more clearly in 2‐DE protein profiles, where it was possible to distinguish the presence/absence, changes in relative abundance and pI/Mr shifts of various protein spots. Proteinase and hyaluronidase zymograms supported the prediction that various isolation protocols result in various profiles of enzymatically active molecules.
Enzyme synthesis and activity assay in microfluidic droplets on a chip
Authors: Wu Nan , Courtois Fabienne , Surjadi Regina , Oakeshott John , Peat Thomas S. , Easton Christopher J. , Abell Christopher , Zhu Yonggang
Published: April 2011

There is growing demand for high‐throughput measurement of biochemical reactions in drug discovery and directed evolution programs. To meet this need, a powerful platform based on droplet‐based bioreactors manipulated by microfluidic systems is being developed, which can overcome the limitations of scale and power encountered in conventional screening methods. This paper reports our progress in the synthesis of enzymes and assay of their activity within a microfluidic droplet system. The model system we use involves the organophosphorus hydrolase enzyme OpdA from Agrobacterium radiobacter and a robust microchip made from polymethyl methacrylate (PMMA). Synthesis of OpdA from cognate DNA within water‐in‐oil droplets was tested using both in‐house and commercial in vitro transcription and translation (IVTT) kits. OpdA activity was measured using coumaphos as substrate and by monitoring the fluorescence released by its product, chlorferone. OpdA was demonstrated to be synthesized and assayed within the droplets using the commercial in vitro transcription and translation kit, although the activity measured within the droplets diminished over time, apparently due to leakage of chlorferone out of the droplets.
Microsystems for personalized biomolecular diagnostics
Authors: Shaw Kirsty J. , Birch Christopher , Hughes Elizabeth M. , Jakes Adam D. , Greenman John , Haswell Stephen J.
Published: April 2011

The development of microfluidic methodology that can be used in conjunction with drug screening and biomolecular diagnostics offers a route to evidence‐based personalized medical care. Ideally, all personal diagnostics are best carried out in a rapid and frequent manner and a microfluidic interface can provide appropriate methodology. The ability to perform genetic analysis or biomarker detection at point‐of‐care would allow the clinician to decide on the most informed course of treatment. Microfluidic systems for biomolecular analysis at all levels, from genes to whole tissue biopsies, have been proposed. Much of the work presented here is at an early stage of development but will consider the range of design considerations together with the plethora of potential applications of integrated microfluidic technology.
Numerical simulation of MHD stagnation point flow and heat transfer of a micropolar fluid towards a heated shrinking sheet
Authors: Ashraf Muhammad , Bashir Sumra
Published: April 2011

A comprehensive study of magneto hydrodynamics two‐dimensional stagnation flow with heat transfer characteristics towards a heated shrinking sheet immersed in an electrically conducting incompressible micropolar fluid in the presence of a transverse magnetic field is analyzed numerically. The governing continuity, momentum, angular momentum and heat equations together with the associated boundary conditions are first reduced to a set of self similar nonlinear ordinary differential equations using a similarity transformation and are then solved by a method based on finite difference discretization. Some important features of the flow and heat transfer in terms of normal and streamwise velocities, microrotation and temperature distributions for different values of the governing parameters are analyzed, discussed and presented through tables and graphs. The results indicate that the reverse flow caused due to shrinking of the sheet can be stopped by applying a strong magnetic field. The magnetic field enhances the shear stresses and decreases the thermal boundary layer thickness. The heat loss per unit area from the sheet decreases with an increase in the shrinking parameter. Micropolar fluids exhibit reduction in shear stresses and heat transfer rate as compared with Newtonian fluids, which may be beneficial in the flow and thermal control of polymeric processing. Copyright © 2011 John Wiley & Sons, Ltd.
An efficient numerical method for solving Falkner–Skan boundary layer flows
Authors: Motsa S. S. , Sibanda P.
Published: April 2011

In this paper a novel computational technique for the solution of nonlinear third‐order boundary value problems is presented. We demonstrate the application of the method by solving the famous Falkner–Skan equation on a semi‐infinite domain. Comparison with the results from other methods such as the homotopy analysis method and numerical methods demonstrates the accuracy, computational efficiency and robustness of this technique. Copyright © 2011 John Wiley & Sons, Ltd.
Adaptive finite element method for an optimal control problem of Stokes flow with L2‐norm state constraint
Authors: Niu Haifeng , Yuan Lei , Yang Danping
Published: April 2011

An adaptive finite element approximation for an optimal control problem of the Stokes flow with an L2‐norm state constraint is proposed. To produce good adaptive meshes, the a posteriori error estimates are discussed. The equivalent residual‐type a posteriori error estimators of the H1‐error of state and L2‐error of control are given, which are suitable to carry out the adaptive multi‐mesh finite element approximation. Some numerical experiments are performed to illustrate the efficiency of the a posteriori estimators. Copyright © 2011 John Wiley & Sons, Ltd.
Penalty finite element method for Navier–Stokes equations with nonlinear slip boundary conditions
Authors: Li Yuan , An Rong
Published: April 2011

The penalty finite element method for Navier–Stokes equations with nonlinear slip boundary conditions is investigated in this paper. Since this class of nonlinear slip boundary conditions include the subdifferential property, the weak variational formulation is a variational inequality problem of the second kind. Using the penalty finite element approximation, we obtain optimal error estimates between the exact solution and the finite element approximation solution. Finally, we show the numerical results which are in full agreement with the theoretical results. Copyright © 2011 John Wiley & Sons, Ltd.
Spectral algorithm for the analysis of flows in grooved channels
Authors: Mohammadi A. , Floryan J. M.
Published: April 2011

A grid‐less, spectrally accurate algorithm for the analysis of flows in grooved channels is presented. The algorithm is based on the immersed boundary conditions concept, where the boundary conditions are submerged inside the computational domain and are treated as internal constraints. When grooves' ridges are orthogonal to the flow direction (transverse grooves), the flow remains two‐dimensional. As the grooves rotate away from this direction, the flow becomes three‐dimensional. An auxiliary coordinate system is defined in such a way that one of its axes is aligned with the grooves. It is shown that the governing equations expressed in this system decouple into a two‐dimensional flow across the grooves and a flow in the direction along the grooves, resulting in improved solution efficiencies. Fourier series are used for discretization in the direction transverse to the grooves and Chebyshev expansions for the direction across the channel. Special solvers that take advantage of the matrix structure have been implemented providing a significant acceleration of computation and reduction of memory requirements. Various tests have been conducted in order to illustrate the performance of the algorithm, to show its spectral accuracy and to characterize the effects of various numerical and physical parameters. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis and redox properties of sterically crowded triarylphosphine and tetraaryldiphosphane bearing phenothiazinyl groups
Authors: Sasaki Shigeru , Murakami Midori , Murakami Fumiki , Yoshifuji Masaaki
Published: April 2011

Sterically crowded triarylphosphines and tetraaryldiphosphane bearing phenothiazinyl groups as redox sites were synthesized by using 2‐bromo‐1,3‐dialkyl‐5‐phenothiazinylbenzenes as key synthetic intermediates. Cyclic voltammograms of these compounds show the first redox wave corresponding to the oxidation of the phosphorus redox center and the following waves corresponding to the oxidation of the phenothiazinyl groups. Introduction of more sterically crowded triarylphosphine moiety leads to more reversible oxidation of the phosphine as well as the phenothiazine moieties. A crowded tetraaryldiphosphane bearing four phenothiazinyl groups are oxidized in two steps. Four phenothiazine moieties are oxidized nearly at once after oxidation of the diphosphane moiety. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:506–513, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20714
Target‐specific output patterns are predicted by the distribution of regular‐spiking and bursting pyramidal neurons in the subiculum
Authors: Kim Yujin , Spruston Nelson
Published: April 2011

Pyramidal neurons in the subiculum project to a variety of cortical and subcortical areas in the brain to convey information processed in the hippocampus. Previous studies have shown that two groups of subicular pyramidal neurons—regular‐spiking and bursting neurons—are distributed in an organized fashion along the proximal–distal axis, with more regular‐spiking neurons close to CA1 (proximal) and more bursting neurons close to presubiculum (distal). Anatomically, neurons projecting to some targets are located more proximally along this axis, while others are located more distally. However, the relationship between the firing properties and the targets of subicular pyramidal neurons is not known. To study this relationship, we used in vivo injections of retrogradely transported fluorescent beads into each of nine different regions and conducted whole‐cell current‐clamp recordings from the bead‐containing subicular neurons in acute brain slices. We found that subicular projections to each area were composed of a mixture of regular‐spiking and bursting neurons. Neurons projecting to amygdala, lateral entorhinal cortex, nucleus accumbens, and medial/ventral orbitofrontal cortex were located primarily in the proximal subiculum and consisted mostly of regular‐spiking neurons (∼80%). By contrast, neurons projecting to medial EC, presubiculum, retrosplenial cortex, and ventromedial hypothalamus were located primarily in the distal subiculum and consisted mostly of bursting neurons (∼80%). Neurons projecting to a thalamic nucleus were located in the middle portion of subiculum, and their probability of bursting was close to 50%. Thus, the fraction of bursting neurons projecting to each target region was consistent with the known distribution of regular‐spiking and bursting neurons along the proximal–distal axis of the subiculum. Variation in the distribution of regular‐spiking and bursting neurons suggests that different types of information are conveyed from the subiculum to its various targets. © 2011 Wiley Periodicals, Inc.
Role of estrogen receptor alpha and beta expression and signaling on cognitive function during aging
Authors: Foster Thomas C.
Published: April 2011

This review presents evidence for the idea that the expression of estrogen receptor alpha and beta (ERα and ERβ) interacts with the level of estradiol (E2) to influence the etiology of age‐related cognitive decline and responsiveness to E2 treatments. There is a nonmonotonic dose response curve for E2 influences on behavior and transcription. Evidence is mounting to indicate that the dose response curve is shifted according to the relative expression of ERα and ERβ. Recent work characterizing age‐related changes in the expression of ERα and ERβ in the hippocampus, as well as studies using mutant mice, and viral mediated delivery of estrogen receptors indicate that an age‐related shift in ERα/ERβ expression, combined with declining gonadal E2 can impact transcription, cell signaling, neuroprotection, and neuronal growth. Finally, the role of ERα/ERβ on rapid E2 signaling and synaptogenesis as it relates to hippocampal aging is discussed. © 2011 Wiley Periodicals, Inc.
Human hippocampal theta oscillations and the formation of episodic memories
Authors: Lega Bradley C. , Jacobs Joshua , Kahana Michael
Published: April 2011

The importance of the hippocampal theta oscillation (4–8 Hz) to memory formation has been well‐established through studies in animals, prompting researchers to propose comprehensive theories of memory and learning that rely on theta oscillations for integrating information in the hippocampus and neocortex. Yet, empirical evidence for the importance of 4–8 Hz hippocampal theta oscillations to memory formation in humans is equivocal at best. To clarify this apparent interspecies discrepancy, we recorded intracranial EEG (iEEG) data from 237 hippocampal electrodes in 33 neurosurgical patients as they performed an episodic memory task. We identified two distinct patterns of hippocampal oscillations, at ∼3 and ∼8 Hz, which are at the edges of the traditional 4–8 Hz human theta band. The 3 Hz “slow‐theta” oscillation exhibited higher power during successful memory encoding and was functionally linked to gamma oscillations, but similar patterns were not present for the 8 Hz “fast‐theta” oscillation. For episodic memory, slow‐theta oscillations in the human hippocampus appear to be analogous to the memory‐related theta oscillations observed in animals. Both fast‐theta and slow‐theta oscillations exhibit evidence of phase synchrony with oscillations in the temporal cortex. We discuss our findings in the context of recent research on the electrophysiology of human memory and spatial navigation, and explore the implications of this result for theories of cortico–hippocampal communication. © 2011 Wiley Periodicals, Inc.
Identification of rainfall–runoff model for improved baseflow estimation in ungauged basins
Authors: Samuel Jos , Coulibaly Paulin , Metcalfe Robert A.
Published: April 2011

Baseflow is an integral component of environmental flow prescriptions to mitigate the impacts of flow regime alteration on the ecological condition of rivers and often the most contentious issue in project planning, particularly for waterpower development. Baseflow prescriptions to meet ecological objectives are increasingly derived from a natural reference condition, often a simulated streamflow time series for an ungauged basin. Accuracy of baseflow estimates is important for identifying ecological water requirements and possible ecosystem and economic tradeoffs with confidence. Estimating baseflow time series in ungauged basins to accurately quantify a natural reference condition in all regions of Ontario is particularly difficult given the heterogeneity in landscape, climate, and size of the basins where simulated time series are required. To identify the optimal hydrologic model for baseflow simulation in all regions of Ontario, five variants of McMaster University‐Hydrologiska Byråns Vattenbalansavdelning (MAC‐HBV) were tested using a combination of possible model parameters, linear and nonlinear storage‐discharge relationship in deep soil layers, and different criteria for optimizing model parameter sets. It was found that the hydrologic model which used a nonlinear storage‐discharge relationship, a larger range of model parameters and included low flow criteria in the optimization procedure showed the best performance for baseflow estimates. The optimal model was then combined with a coupled regionalization method to improve baseflow estimates in ungauged basins compared with the original MAC‐HBV model. This included a ∼20% increase in the median of Nash Sutcliffe efficiencies and a 50% reduction in the volume errors for the tested basins. The resulting model provides a tool that can be used reliably throughout Ontario to simulate streamflow and baseflow time series in ungauged basins and to calculate baseflow indicators and criteria for aquatic ecosystem assessments of planned flow regime alterations. Copyright © 2011 John Wiley & Sons, Ltd.
Uncertainty in index flood modelling due to calibration data sizes
Authors: Wan Jaafar Wan Zurina , Han Dawei
Published: April 2011

Regional frequency analysis is an important tool in estimating design flood for ungauged catchments. Index flood is an important component in regionalized flood formulas. In the past, many formulas have been developed based on various numbers of calibration catchments (e.g. from less than 20 to several hundred). However, there is a lack of systematic research on the model uncertainties caused by the number of calibration catchments (i.e. what is the minimum number of calibration catchment? and how should we choose the calibration catchments?). This study uses the statistical resampling technique to explore the impact of calibration catchment numbers on the index flood estimation. The study is based on 182 catchments in England and an index flood formula has been developed using the input variable selection technique in the data mining field. The formula has been used to explore the model uncertainty due to a range of calibration catchment numbers (from 15 to 130). It is found that (1) as expected, the more catchments are used in the calibration, the more reliable of the models developed are (i.e. with a narrower band of uncertainty); (2) however, poor models are still possible with a large number of calibration catchments (e.g. 130). In contrast, good models with a small number of calibration catchments are also achievable (with as low as 15 calibration catchments). This indicates that the number of calibration catchments is only one of the factors influencing the model performance. The hydrological community should explore why a smaller calibration data set could produce a better model than a large calibration data set. It is clear from this study that the information content in the calibration data set is equally if not more important than the number of calibration data. Copyright © 2011 John Wiley & Sons, Ltd.
Evapotranspiration and crop coefficient for a temperate desert steppe ecosystem using eddy covariance in Inner Mongolia, China
Authors: Zhang Feng , Zhou Guangsheng , Wang Yu , Yang Fulin , Nilsson Christer
Published: April 2011

Evapotranspiration (ET), which links water, energy and the carbon cycle in terrestrial ecosystems, is an important eco‐hydrological process, especially in arid and semi‐arid regions. To determine the crop coefficient (Kc) over a 2‐year period for a temperate desert steppe in Inner Mongolia, China, ET was measured using the eddy covariance method and the reference evapotranspiration (ET0) was estimated from site meteorological data. The results showed that the seasonal variation of ET differed on an annual timescale between the 2 consecutive years, exhibiting a multi‐peak curve in 2008 and a single peak in 2009. The mean daily Kc values were 0·15 and 0·17 in 2 years, varying from 0·009 to 0·75 in 2008 and from 0·005 to 0·58 in 2009. The 5‐day moving average for Kc values was mainly affected by SWC10cm and Rn, and the regression coefficients (R2) were 58·9 and 69·5%, respectively. These results will aid in making accurate and quantitative assessments of the vulnerability of the sparse vegetation to climate change. Copyright © 2011 John Wiley & Sons, Ltd.
Linking metrics of hydrological function and transit times to landscape controls in a heterogeneous mesoscale catchment
Authors: Capell R. , Tetzlaff D. , Hartley A. J. , Soulsby C.
Published: April 2011

Long‐term river flow data and one year of isotopic tracer data in a nested 749 km2 catchment were analysed conjunctively to evaluate the relationships between hydrometric statistics, transit times, and catchment characteristics. The catchment comprised two distinct geomorphic provinces; upland headwaters draining glaciated landscapes underlain by crystalline geology and lowland headwaters draining a major regional sandstone aquifer. In the uplands, flow regimes were ‘flashy’ with high runoff coefficients for storm hydrographs, steep recession curves and strong nonlinearity in event responses. In the lowlands, runoff coefficients were low, recessions less steep, and event responses more linear. Flow data from the catchment outfall showing damping of these extremes, but was most strongly influenced by the upland headwaters where precipitation was highest. The damping of variability in stable water isotopes between precipitation inputs and streamflow outputs reflected this; with upland tributaries least damped and lowland tributaries most damped. Attempts to quantify the mean transit times of the sampling points met with mixed success; partly reflecting the short run (1 year) of data, but mainly as a result of the marked damping in lowland sites. As a consequence, MTT estimates can only be said to be in the order of a few years in upland sites, but are probably decadal or greater in lowland tributaries. Again, the catchment outfall averages these extremes, but is more similar to the upland headwaters. Despite the difficulties in quantifying MTTs, it is clear that they, like the hydrological response, primarily reflect the dominant control of catchment soil cover, which in turn is determined by geology and glacial history. Copyright © 2011 John Wiley & Sons, Ltd.
Spatial distribution and temporal variation of reference evapotranspiration in arid and semi‐arid regions of Iran
Authors: Tabari Hossein , Aeini Ali , Talaee P. Hosseinzadeh , Some'e B. Shifteh
Published: April 2011

Analysis of spatial and temporal variations of reference evapotranspiration (ETo) is important in arid and semi‐arid regions where water resources are limited. The main aim of this study was to analyse the spatial distribution and the annual, seasonal and monthly trends of the Penman–Monteith ETo for 21 stations in the arid and semi‐arid regions of Iran. Three statistical tests the Mann‐Kendall, Sen's slope estimator and linear regression were used for the analysis. The analysis revealed that ETo increased from January to July and deceased from July to December at almost all stations. Additionally, higher annual ETo values were found in the southeast of the study region and lower values in the northwest of the region. Although the results showed both positive and negative trends in annual ETo series, ETo generally increased, significantly so in six (∼30%) of the stations. Analysis of the impacts of meteorological variables on the temporal trends of ETo indicated that the increasing trend of ETo was most likely due to a significant increase in minimum air temperature, while decreasing trend of ETo was mainly caused by a significant decrease in wind speed. At the sites where increasing ETo trends were statistically significant, the rate of increase varied from (+)8·36 mm/year at Mashhad station to (+)31·68 mm/year at Iranshahr station. On average, an increasing trend of (+)4·42 mm/year was obtained for the whole study area during the last four decades. Seasonal and monthly ETo have also tended to increase at the majority of the stations. The greatest numbers of significant trends were observed in winter on the seasonal time‐scale and in September on the monthly time‐scale. Copyright © 2011 John Wiley & Sons, Ltd.
Variations in water and CO2 fluxes over a saline desert in western China
Authors: Liu Ran , Li Yan , Wang Qin‐Xue
Published: April 2011

We studied the variations in water and carbon dioxide fluxes of a saline desert in western China using the eddy covariance technique. In addition, bare‐soil evaporation was measured using the micro‐lysimeter method. The following three inquiries were made: (1) the magnitude of evapotranspiration (ET) and net ecosystem carbon exchange (NEE) and how these components vary seasonally; (2) how NEE and ET vary following rain pulses of different magnitudes; and (3) how ET divides into evaporation and transpiration and its relationship to carbon dioxide exchange. The saline desert acted as a net C sink of − 49 g C m−2 year−1, with a gross ecosystem productivity (GEP) of 345 g C m−2 year−1 and an ecosystem respiration (Reco) of 296 g C m−2 year−1. Rainfall pulses exerted strong control over ecosystem‐scale water and CO2 fluxes. There was a 1 to 2 days lag in maximal ET despite the magnitude of rainfall pulses, while NEE took 4–5 days to reach its peak if the rainfall was large enough to increase the photosynthetic activity of vascular plants. Overall, the ratio of total transpiration to ET was 38%, but it was about 92% during the months when the vascular plants were active. The NEE was increasingly more negative as the growing season progressed, indicating a greater net uptake of CO2 and a greater water use efficiency. Copyright © 2011 John Wiley & Sons, Ltd.