bluuebunny/crossref_metadata_2025 huggingface dataset:
Incidence and Location of Focal Atrial Fibrillation Triggers in Patients Undergoing Repeat Pulmonary Vein Isolation:
Authors: Gerstenfeld Edward P. , Callans David J. , Dixit Sanjay , Zado Erica , Marchlinski Francis E.
Published: August 2010

Introduction: The etiology of atrial fibrillation (AF) recurrences after pulmonary vein (PV) isolation is not well described. The aim of this study was to examine the reason for recurrent AF in patients undergoing a repeat attempt at AF trigger ablation.

Methods and Results: Patients with recurrent AF more than 1 month after ablation returned for repeat mapping and ablation. A circular mapping catheter was advanced to each previously targeted PV ostium to determine if the PV was still electrically isolated. Ectopy then was provoked with isoproterenol (up to 20 μg/min), burst pacing, and pacing into AF followed by cardioversion. The location of ectopy triggering atrial premature depolarizations (APDs) or AF was noted. Of 226 patients who underwent ablation of AF triggers, 34 (8 women and 26 men; age 56 ± 10 years) with recurrent AF returned for a repeat procedure 207 ± 183 days after the first procedure. There were 84 previously completely isolated PVs in these 34 patients. Thirty‐three (39%) of 84 previously isolated PVs were still completely isolated at the time of the second procedure. Fifty‐one PVs (61%) had evidence of recovered PV potentials. Fifty triggers of APDs and AF (n = 30) or APDs only (n = 20) were identified in these 34 patients. The majority of triggers [27/50 (54%)] originated from previously targeted PVs. Sixteen triggers [16/50 (32%)] originated from previously nontargeted PVs.

Conclusion: The majority of AF recurrences originate from previously isolated PVs. One third of recurrent triggers originated from PVs that were not targeted during the initial ablation session. Although empiric isolation of all PVs may reduce recurrences, strategies to ensure ostial PV isolation and to prevent recurrent PV conduction after ablation should have the greatest impact on reducing AF recurrence. (J Cardiovasc Electrophysiol, Vol. 14, pp. 685‐690, July 2003)
Linkage Between Mechanical and Electrical Alternans in Patients with Chronic Heart Failure
Authors: KODAMA MAKOTO , KATO KIMINORI , HIRONO SATORU , OKURA YUJI , HANAWA HARUO , YOSHIDA TSUYOSHI , HAYASHI MANABU , TACHIKAWA HITOSHI , KASHIMURA TAKESHI , WATANABE KENICHI , AIZAWA YOSHIFUSA
Published: August 2010

Introduction: Progressive heart failure and ventricular fibrillation are major causes of death in patients with chronic heart failure. Mechanical alternans (pulsus alternans) has been observed in patients with severe congestive heart failure. Visible T wave alternans occasionally is a precursor of ventricular fibrillation. We investigated the occurrence of both cardiac alternans in 94 patients with chronic heart failure.

Methods and Results: Mean left ventricular ejection fraction (LVEF) of the study population was 35 ± 10%. Mechanical alternans was detected in left ventricular pressure during diagnostic cardiac catheterization. Only sustained mechanical alternans was included in the study. Visible T wave alternans, not microvolt alternans, was noted on standard surface ECG. Cardiac alternans was examined at rest, during physiologic tachycardia, and during stepwise dobutamine loading (2–4–8 μg/kg/min). Prevalences of mechanical and electrical alternans were 19.1% and 4.4% at rest, 45.5% and 8.0% during physiologic tachycardia, and 62.1% and 9.5% under dobutamine loading. Overall, 70 patients (74.5%) showed mechanical alternans and 10 patients (10.6%) showed T wave alternans. T wave alternans always appeared with large mechanical alternans. Among patients with mechanical alternans, cases with T wave alternans showed lower LVEF than those without (27.5 ± 4.4 and 35.1 ± 10.2, P < 0.002).

Conclusion: Visible T wave alternans was detectable in patients with chronic heart failure, especially under tachycardia or catecholamine exposure. Investigating mechanical and mechanoelectrical alternans may bring new insights into the management of patients with chronic heart failure. (J Cardiovasc Electrophysiol, Vol. 15, pp. 295‐299, March 2004)
Reversal of Electrical Remodeling After Cardioversion of Persistent Atrial Fibrillation
Authors: RAITT MERRITT H. , KUSUMOTO WALTER , GIRAUD GEORGE , MCANULTY JOHN H.
Published: August 2010

Introduction: In animals, atrial fibrillation results in reversible atrial electrical remodeling manifested as shortening of the atrial effective refractory period, slowing of intra‐atrial conduction, and prolongation of sinus node recovery time. There is limited information on changes in these parameters after cardioversion in patients with persistent atrial fibrillation.

Methods and Results: Thirty‐eight patients who had been in atrial fibrillation for 1 to 12 months underwent electrophysiologic testing 10 minutes and 1 hour after cardioversion. At 1 week, 19 patients still in sinus rhythm returned for repeat testing. Reverse remodeling of the effective refractory period was not uniform across the three atrial sites tested. At the lateral right atrium, there was a highly significant increase in the effective refractory period between 10 minutes and 1 hour after cardioversion (drive cycle length 400 ms: 204 ± 17 ms vs 211 ± 20 ms, drive cycle length 550 ms: 213 ± 18 ms vs 219 ± 23 ms, P < 0.001). The effective refractory period at the coronary sinus and distal coronary sinus did not change in the first hour but had increased by 1 week. The corrected sinus node recovery time did not change in the first hour but was shorter at 1 week (606 ± 311 ms vs 408 ± 160 ms, P = 0.009). P wave duration also was shorter at 1 week (135 ± 18 ms vs 129 ± 13 ms, P = 0.04) consistent with increasing atrial conduction velocity.

Conclusion: The atrial effective refractory period increases, sinus node function improves, and atrial conduction velocity goes up in the first week after cardioversion of long‐standing atrial fibrillation in humans. Reverse electrical remodeling of the effective refractory period occurs at different rates in different regions of the atrium. (J Cardiovasc Electrophysiol, Vol. 15, pp. 507‐512, May 2004)
Acute Effects of Left Atrial Radiofrequency Ablation on Atrial Fibrillation
Authors: SCHARF CHRISTOPH , ORAL HAKAN , CHUGH AMAN , HALL BURR , GOOD ERIC , CHEUNG PETER , PELOSI FRANK , MORADY FRED
Published: August 2010

Introduction: Acutely, when left atrial ablation is performed during atrial fibrillation (AF), the AF may persist and require cardioversion, or it may convert to sinus rhythm or to atrial tachycardia/flutter. The prevalence of these acute outcomes has not been described.

Methods and Results: Left atrial ablation, usually including encirclement of the pulmonary veins, was performed during AF in 144 patients with drug‐refractory AF. Conversion to sinus rhythm occurred in 19 patients (13%), to left atrial tachycardia in 6 (4%), and to atrial flutter in 6 (4%). In the 6 patients with a focal atrial tachycardia, the mean cycle length was 294 ± 45 ms. The tachycardia arose in the left atrial roof in 3 patients, the left atrial appendage in 2, and the anterior left atrium in 1. In 3 of 6 patients, the focal atrial tachycardia originated in an area that displayed a relatively short cycle length during AF. In 6 patients, AF converted to macroreentrant atrial flutter with a mean cycle length of 253 ± 47 ms, involving the mitral isthmus in 5 patients and the septum in 1 patient. All atrial tachycardias and flutters were successfully ablated with 1 to 15 applications of radiofrequency energy.

Conclusion: When left atrial ablation is performed during AF, the AF may convert to atrial tachycardia or flutter in approximately 10% of patients. Focal atrial tachycardias that occur during ablation of AF may be attributable to driving mechanisms that persist after AF has been eliminated, whereas atrial flutter results from incomplete ablation lines. (J Cardiovasc Electrophysiol, Vol. 15, pp. 515‐521, May 2004)
Conduction Characteristics at the Crista Terminalis During Onset of Pulmonary Vein Atrial Fibrillation
Authors: FYNN SIMON P. , MORTON JOSEPH B. , DEEN VINCENT R. , KISTLER PETER M. , VOHRA JITENDRA K. , SPARKS PAUL B. , KALMAN JONATHAN M.
Published: August 2010

Introduction: Focal atrial fibrillation (AF) may initiate with an irregular rapid burst of atrial ectopic (AE) activity from a pulmonary vein (PV) focus, but how AF is maintained it is not known. The crista terminalis (CT) is an important line of block in atrial flutter (AFL), but its role in AF has not been determined. The aim of this study was to examine the conduction properties of the CT during onset of AF.

Methods and Results: In 10 patients (mean age 38 ± 8 years), we analyzed conduction across the CT during onset of focal AF from an arrhythmogenic PV and during pacing from the same PV at cycle lengths of 700 and 300 ms. A 20‐pole catheter was positioned on the CT using intracardiac echocardiography. In 10 control patients with no history of AF, we analyzed conduction across the CT during pacing from the distal coronary sinus at 700 and 300 ms. In all 10 AF patients, AF was initiated with 1 to 9 AE beats (median 5) from a PV. During sinus rhythm, there were no split components (SC) recorded on the CT. During PV AE activity, discrete SC were recorded on the CT in all patients over 6.3 ± 0.9 bipoles (3.7 ± 0.3 cm). Maximal splitting of SC was 66 ± 31 ms (37–139). There was an inverse relationship between AE coupling intervals and the degree of splitting between SC in all patients. Degeneration to AF was preceded by progressive decrement across the CT. SC were recorded during PV pacing at 700 and 300 ms (maximal distance between SC of 24 ± 3 ms and 43 ± 5 ms, respectively, P < 0.001). Maximum SC at CT in controls was 13 ± 8 ms at 700 ms (P = 0.06 vs AF patients) and 16 ± 9 ms at 300 ms (P < 0.01 vs AF patients).

Conclusion: (1) These observations provide evidence of anisotropic, decremental conduction across the CT during onset of focal AF and during pacing from the same PV. A line of functional conduction block develops along this anatomic structure (CT). Whether this line of block acts as an initiator of AF or simply contributes passively to nonuniform fibrillatory conduction is unknown. (2) In some patients with focal AF, development of conduction block along the CT may provide a substrate for typical AFL.
Measuring Patient Acceptance of Implantable Cardiac Device Therapy:
Authors: BURNS JASON L. , SERBER EVA R. , KEIM STEPHEN , SEARS SAMUEL F.
Published: August 2010

Introduction: Patient acceptance of implantable device therapy has been established as an important outcome but the operationalization and validation of a measure of patient acceptance of implantable device therapy has not been fully completed. This study sought to validate a new measure of patient acceptance of cardiac implantable devices called the Florida Patient Acceptance Survey (FPAS).

Methods: The sample consisted of implantable cardioverter defibrillator (ICD; n = 58), and implantable atrioverter defibrillator (ICD‐AT; n = 96), and pacemaker (PM, n = 84) patients. Mean age of all participants was 69 years; they were mostly male (62%) and married (75%). The final FPAS comprised 15 items with four consistent factors: Return to Function, Device‐Related Distress, Positive Appraisal, and Body Image Concerns.

Results: The total FPAS demonstrated good internal consistency (Cronbach's alpha = 0.83), and internal consistency for each of the subscales ranged from 0.74 to 0.89. The FPAS demonstrated convergent, divergent, and discriminant validity when compared to other self‐report measures of QOL, atrial symptoms, depression, and anxiety. A total FPAS score can be formed and between group comparisons with this sample indicated that ICD patients report a high level of acceptance (mean = 76), ICD‐AT patients report a significantly higher level of acceptance (mean = 81.1), and PM patients reported the highest level of patient acceptance (mean = 85.4) of these implantable device groups.

Conclusion: This initial psychometric investigation of the FPAS suggests that the FPAS may be useful in both clinical and research settings to assess patient acceptance of implantable cardiac devices.
Induction Ovens and Electromagnetic Interference:  What Is the Risk for Patients with Implantable Cardioverter Defibrillators?
Authors: BINGGELI CHRISTIAN , RICKLI HANS , AMMANN PETER , BRUNCKHORST CORINNA , HUFSCHMID URS , LUECHINGER ROGER , DURU FIRAT
Published: August 2010

Electromagnetic fields may interfere with normal implantable cardioverter defibrillator (ICD) function. Although the devices are effectively shielded and use exclusively bipolar leads, electromagnetic interference (EMI) remains a concern when patients are exposed to several household appliances. The aim of this study was to evaluate potential EMI risk of induction ovens, which are increasingly common in private households. In vitro measurements of an induction oven for private households GK 43 TI (V‐Zug, Inc., Zug, Switzerland) showed that heating is regulated by increasing operating time from level 1 (100 ms/sec) to 5 (continuous operation). From levels 5 to 9 the magnetic field increases. Nineteen patients with left‐sided implants of single‐ and dual‐chamber ICD systems (8 Medtronic, 7 Guidant, and 4 St. Jude Medical) (18 males, 1 female), age (mean ± SEM) 58 ± 3 years, were included in this study. All patients were examined in standing position, bent over the cooking pot (minimal distance to the induction coil 25 cm), and with the cooking pot put eccentrically over the induction field at three different cooking levels (level 2, 5, and 9). The tests were repeated touching the cooking pot with one hand. Ventricular sensitivity was left unchanged. Ventricular tachycardia therapies were turned off in Medtronic and Guidant devices and ventricular sensing was continuously monitored in St. Jude Medical devices during testing. Interrogation of the devices after exposure did not show any inappropriate tachycardia detection, oversensing, or reprogramming. In conclusion, ICD patients can be reassured that EMI is unlikely to affect their devices if induction ovens are used in their kitchens.
Short QT Syndrome and Atrial Fibrillation Caused by Mutation in KCNH2
Authors: HONG KUI , BJERREGAARD PREBEN , GUSSAK IHOR , BRUGADA RAMON
Published: August 2010

Background: The short QT syndrome is a newly described clinical entity characterized by the presence of a short QT interval associated with cardiac tachyarrhythmias including sudden cardiac death at a young age in otherwise healthy individuals. A genetic basis has been identified linking the disease to mutations in KCNH2 in the familial forms and a mutation in KCNQ1 in a sporadic form of the disease.

Methods and Results: We identified a family with short QT syndrome with a high incidence of paroxysmal atrial fibrillation in their members and no known history of sudden cardiac death. QT interval ranged from 225 to 240 ms within normal heart rate ranges in the affected individuals. Programmed electrical stimulation (PES) was performed in all affected members, which revealed a remarkably short atrial and ventricular refractory period, and inducibility of atrial and ventricular fibrillation. Treatment with propafenone has maintained the individuals free of atrial fibrillation to date. Genetic analysis identified a missense mutation (C to G substitution at nucleotide 1764) which resulted in the amino acid change (N588K) in KCNH2. This mutation had been previously described in two other families with a high incidence of sudden cardiac death.

Conclusions: Our study confirms that N588K is a hotspot for familial form of the short QT syndrome. The disease is clinically heterogeneous, as indicated by the fact that, in the three families with the same mutation, there is a wide range of symptoms, varying from atrial to ventricular fibrillation and sudden death. While the implantation of a defibrillator appears warranted due to the inducibility at PES, the clinical follow‐up provides indication that the class Ic agent propafenone could be effective to prevent episodes of paroxysmal atrial fibrillation.
The Inferior Right Atrial Isthmus: Further Architectural Insights for Current and Coming Ablation Technologies
Authors: CABRERA JOSÉ ANGEL , SÁNCHEZ‐QUINTANA DAMIAN , FARRÉ JERÓNIMO , RUBIO JOSÉ MANUEL , HO SIEW YEN
Published: August 2010

Background: Although linear ablation of the right atrial isthmus in patients with isthmus‐dependent atrial flutter can be highly successful, recurrences and complications occur in some patients. Our study provides further morphological details for a better understanding of the structure of the isthmus.

Methods and Results: We examined the isthmic area in 30 heart specimens by dissection, histology, and scanning electron microscopy. This area was bordered anteriorly by the hinge of the tricuspid valve and posteriorly by the orifice of the inferior caval vein. With the heart in attitudinal orientation, we identified and measured the lengths of three levels of isthmus: paraseptal (24 ± 4 mm), central (19 ± 4 mm), and inferolateral (30 ± 3 mm). Comparing the three levels, the central isthmus had the thinnest muscular wall and the paraseptal isthmus the thickest wall. At all three levels, the anterior part was consistently muscular whereas the posterior part was composed of mainly fibro‐fatty tissue in 63% of hearts. The right coronary artery was less than 4 mm from the endocardial surface of the inferolateral isthmus in 47% of hearts. Inferior extensions of the atrioventricular node were present in the paraseptal isthmus in 10% of hearts, at 1–3 mm from the endocardial surface.

Conclusions: The thinner wall and shorter length of the central isthmus together with its distance from the right coronary artery, and nonassociation with the atrioventricular node or its arterial supply, should make it the preferred site for linear radiofrequency ablation.
Traiter orthopédiquement les asymétries avant six ans ou
comment symétriser la croissance cranio-faciale et optimiser le fonctionnement
temporo-mandibulaire
Authors: Deshayes Marie-Josèphe
Published: August 2010

La mise en évidence de petites asymétries faciales chez le nourrisson montre que sa
croissance faciale va devenir asymétrique. L’examen en denture lactéale des déplacements
mandibulaires peut révéler une fonction masticatoire asymétrique et implique la recherche
d’une asymétrie axiale inter-temporale grâce au tracé de repères pris sur les oreilles
externes. S’ils indiquent un remodelage asymétrique des cavités glénoïdes, cela fait
craindre des désordres ultérieurs des ATM. L’utilisation d’une grille de mesure, type
Orthogrille, posée sur le moulage supérieur, permet de rechercher une asymétrie
positionnelle sagittale et/ou transversale des dents temporaires. La correction de ces
asymétries est faite avec la plaque palatine équipée de vérins sectoriels : actions de
distalisation avec ou sans action latérale, partielle ou totale. On modifie également
l’inclinaison du plan occlusal supérieur avec des pistes de désocclusion totale. Les
déplacements mandibulaires redeviennent symétriques pendant la mastication et induisent un
remodelage symétrique des os temporaux. Enfin, on recentre les deux arcades sur un Frankel
de recentrage et l’on symétrise les fonctions de respiration et de production des sons.
Grâce à ce type de traitement orthopédique conduit avant l’âge de 6 ans, la trajectoire de
croissance faciale à l’origine asymétrique peut redevenir symétrique et optimiser le
fonctionnement temporo-mandibulaire.
Community Referrals — Opportunities for Improvements
Authors: Haraldsdóttir Hrefna
Published: August 2010

The pharmaceutical regulatory environment in Europe has changed dramatically over the past two decades with the establishment of the European Economic Area Agreement and the European Union. The Community has instituted a progressive programme of harmonising medicines legislation with the objective of creating a genuine single market in the pharmaceutical sector, while ensuring a high level of public health protection. This article analyses the Community referral procedures for medicinal products for human use that are used to resolve disagreements between member states. The results are used not only to identify opportunities for improvement in the referral process but also to indicate to the applicant possible improvements in registration strategy.
Medicine for Tomorrow: Some Alternative Proposals to Promote Socially Beneficial Research and Development in Pharmaceuticals
Authors: Stiglitz Joseph E. , Jayadev Arjun
Published: August 2010

The current models of pharmaceutical drug discovery display significant inefficiencies. One inefficiency is the widespread prevalence of me-too drugs. Second, some patents can act as barriers to knowledge, by slowing down the pace of new discoveries. Third, there are higher costs for the public, who end up paying double costs — subsidizing or funding research and development (R & D) that leads to new discoveries on the one hand, and, on the other, paying the social costs of restricted access to knowledge when the discoveries are privatized. Fourth, when the market returns are the sole guide to R & D of new drugs, diseases that are prevalent in markets with weaker buying power are neglected. Thus, policymakers need to identify a new, more cost-effective and innovative productive system for R & D. Policymakers are faced with very complex choices in designing their regulations. They want to promote access to medicines, to lower costs and to encourage research. Politically, they have to balance pressure from the industry with increasingly forceful demands from health advocacy groups. The article looks at four different sorts of policies that may be used to address some of the inadequacies in the current system, especially with regard to the management of R & D: promoting prizes over patents; directing innovation toward socially beneficial outputs by adopting some form of value-based pricing; publicly funding clinical trials to reduce conflicts of interest while reducing costs; and actively managing frontier technologies to maximize positive social spillovers.
Chirped Gaussian laser beam parameters in paraxial approximation
Authors: Sohbatzadeh F. , Mirzanejhad S. , Aku H. , Ashouri S.
Published: August 2010

In this paper, new expressions for spot size, radius of curvature, and Rayleigh length of a linearly and negatively chirped Gaussian beam are presented in paraxial approximation self-consistently. It is shown that there is a slight modification in those relations in comparison to that of used in literatures. These modifications change the tailored parameters in some laser beam interactions such as laser electron vacuum acceleration. At propagation distances much grater than the Rayleigh length, the modifications indicate that the temporal shape of the chirped laser beam will be changed. This effect indicates an asymmetric pulse with a slowly increasing front part and a suddenly dropping tail. For propagation distances less than the Rayleigh length, the change in laser pulse shape is not considerable. Finally, the modifications are employed in modeling of a single electron acceleration by the chirped Gaussian laser pulse.
The solid solution Gd2NixCu2−xMg: Large reversible magnetocaloric effect and a drastic change of the magnetism by substitution
Authors: Linsinger Stefan , Hermes Wilfried , Eul Matthias , Pöttgen Rainer
Published: August 2010

Various samples of the solid solution Gd2NixCu2−xMg were synthesized from the elements in sealed tantalum ampoules in an induction furnace. All members crystallize with the tetragonal Mo2FeB2 type structure, space group P4/mbm, and they were characterized on the basis of Guinier powder patterns and energy dispersive X-rays analyses. The lattice parameters decrease with increasing nickel content in a Vegard-like manner. The Gd2NixCu2−xMg samples show Curie–Weiss behavior with slightly higher magnetic moment values than the theoretical one for a free Gd3+ ion. The substitution of copper by nickel has a drastic influence on the magnetism and magnetic ordering temperature. For Gd2Ni0.5Cu1.5Mg a temperature induced FM→AFM order-to-order transition was observed, whereas Gd2Ni1.0Cu1.0Mg is a metamagnet with HCr of about 8 kOe at 5 K. For both compounds, a large reversible magnetocaloric effect (MCE) near their ordering temperatures occurs. The values of the maximum magnetic entropy change −ΔSMmax reach 9.5 and 11.4 J kg−1 K−1 for the field change of 5 T with no obvious hysteresis loss around 65 K for Gd2Ni0.5Cu1.5Mg and Gd2Ni1.0Cu1.0Mg, respectively. The corresponding relative cooling power with 688 and 630 J kg−1 is relatively high as compared to other MCE materials in that temperature range. These results indicate that Gd2NixCu2−xMg could be a promising system for magnetic refrigeration at temperatures below liquid N2.
Flow-induced polymer translocation through narrow and patterned channels
Authors: Nikoubashman Arash , Likos Christos N.
Published: August 2010

We consider linear and branched polymers driven through narrow and patterned channels by imposing a Poiseuille flow on the ambient solvent. We establish, by means of scaling arguments, that the translocation probability of dendrimers through the pore is independent of the number of monomers and that it takes place above a viscosity-dependent critical external current. When the channel walls are smooth, the translocation times of linear and branched polymers with the same monomer number are very similar. However, for walls that are decorated with attractive patches, dramatic differences show up: whereas a dendrimer successively docks at the patches and “walks” from one to the next, being carried away by the solvent flow, linear chains spread themselves along the channel wall without achieving translocation within simulation times. Our findings are relevant for, e.g., drug delivery through dendritic carrier molecules in capillary arterioles.
Short range scattering mechanism of type-II GaSb/GaAs quantum dots on the transport properties of two-dimensional electron gas
Authors: Li Guodong , Yin Hong , Zhu Qinsheng , Sakaki Hiroyuki , Jiang Chao
Published: August 2010

We have studied the scattering process of AlGaAs/GaAs two-dimensional electron gas with the nearby embedded GaSb/GaAs type-II quantum dots (QDs) at low temperature. Quantum Hall effect and Shubnikov–de Haas oscillation were performed to measure the electron density n2D, the transport lifetime τt, and the quantum lifetime τq under various biased gate voltage. By comparing measured results of QDs sample with that of reference sample without embedded QDs, mobilities (transport mobility μt and quantum mobility μq) dominated by GaSb QDs scattering were extracted as functions of n2D. It was found that the ratios of τt to τq were varying within the range of 1–4, implying the scattering mechanism belonging to the sort of short-range interaction. In the framework of Born approximation, a scattering model considering rectangular-shaped potential with constant barrier height was successfully applied to explain the transport experimental data. In addition, an oscillating ratio of τt/τq with the increasing n2D was predicted in the model.
Amorphous copper tungsten oxide with tunable band gaps
Authors: Chen Le , Shet Sudhakar , Tang Houwen , Ahn Kwang-soon , Wang Heli , Yan Yanfa , Turner John , Al-Jassim Mowafak
Published: August 2010

We report on the synthesis of amorphous copper tungsten oxide thin films with tunable band gaps. The thin films are synthesized by the magnetron cosputtering method. We find that due to the amorphous nature, the Cu-to-W ratio in the films can be varied without the limit of the solubility (or phase separation) under appropriate conditions. As a result, the band gap and conductivity type of the films can be tuned by controlling the film composition. Unfortunately, the amorphous copper tungsten oxides are not stable in aqueous solution and are not suitable for the application of photoelectrochemical splitting of water. Nonetheless, it provides an alternative approach to search for transition metal oxides with tunable band gaps.
Terahertz superconductor metamaterial
Authors: Gu Jianqiang , Singh Ranjan , Tian Zhen , Cao Wei , Xing Qirong , He Mingxia , Zhang Jingwen W. , Han Jiaguang , Chen Hou-Tong , Zhang Weili
Published: August 2010

We characterize the behavior of split ring resonators made up of high transition temperature yttrium barium copper oxide superconductor using terahertz time-domain spectroscopy measurements and numerical simulations. The superconductor metamaterial is found to show a remarkable change in the transmission spectra at the fundamental inductive-capacitive resonance as the temperature dips below the critical transition temperature. This resonance switching effect is normally absent in traditional metamaterials made up of regular metals. The temperature-dependent resonance behavior of the superconducting metamaterial would lead to development of low loss terahertz switches at cryogenic temperatures.
High electron mobility In2O3(001) and (111) thin films with nondegenerate electron concentration
Authors: Bierwagen Oliver , Speck James S.
Published: August 2010

Temperature dependent Hall measurements were applied to demonstrate, semiconducting n-type high-quality In2O3(001) and (111) thin films with nondegenerate unintentionally doped (UID) electron concentrations on the order of 1017 cm−3 at room temperature, which is below those of bulk single crystals. The freeze-out of the electron concentration in all samples suggests a shallow UID donor with ionization energy in the 17 meV range. Postgrowth annealing in oxygen allowed to further decrease the UID electron concentration with simultaneous mobility increase, suggesting oxygen vacancies to be the shallow UID donors. Hall mobilities above 200 cm2/V s at room temperature and 1000 cm2/V s at low temperatures exceed those of bulk single crystals and demonstrate high material quality and purity.
Self-phase modulation at visible wavelengths in nonlinear ZnO channel waveguides
Authors: Teraoka Edgar Yoshio Morales , Broaddus Daniel H. , Kita Tomohiro , Tsukazaki Atsushi , Kawasaki Masashi , Gaeta Alexander L. , Yamada Hirohito
Published: August 2010

We report the observation of nonlinear optical effects in the visible spectrum using ZnO channel waveguides. We demonstrate sixfold spectral broadening and a 2π phase shift due to self-phase modulation in ZnO channel waveguides using femtosecond optical pulses with a center wavelength of 840 nm. We measured a value for the nonlinear parameter γ of 13.9±3.0 W−1 m−1, which is more than 1300 times that of a highly nonlinear fiber. The calculated intensity-dependent refractive index is found to be consistent with previously reported values of bulk single-crystal ZnO.
Regional Economic Policy ‘In-the-Making’: Imaginaries, Political Projects and Institutions for Auckland's Economic Transformation
Authors: Wetzstein Steffen , Le Heron Richard
Published: August 2010

This paper explores the utility of investigating regional economic policy (REP) as constituted through the interplay of imaginaries, political projects, and institutional arrangements. It frames REP in process terms—as continually ‘in-the-making’ and emerging out of the intersecting trajectories of ideas, policy, individuals, and other resources. The empirical focus is economic governance in Auckland, New Zealand, in the years following the widely publicised neoliberal reforms and profound economic restructuring of the 1980s and early 1990s. The analysis draws on the authors' particular positionality of being involved in knowledge production, both in academic and in policy arenas, and benefits from the development of a range of poststructural political economy methodologies by Auckland-based researchers. The concept of ‘political project’ is argued to be a useful analytical tool for linking circulating academic imaginaries, political initiatives, and particular policy rationales. By means of juxtaposing key aspects of particular economic imaginaries with political/policy initiatives and developments, it is shown that knowledge production for subnational economic governance is coconstitutive, contradictory, occurs on multiple geographical scales, and is mediated and remediated by place-specific and time-specific institutional actors. The methodological strategy of highlighting associations with the potential for interaction, rather than seeking causal processes, not only reveals the politicised nature of contextual facets of contemporary interventions, but promises to make a richer base for exploring possibilities for acting differently in urban and regional policy worlds.
Low-Income-Country Import Competition and the Structure of Earnings Inequality in Canada, 1996–2001
Authors: Breau Sébastien
Published: August 2010

This paper uses a detailed employer–employee dataset to test the effects of low-income-country import competition on the earnings of workers in manufacturing industries in Canada. From 1996 to 2001 earnings inequality increased: the wage gap between manufacturing workers with a university degree and those without a high school diploma rose from 35% to 43%. Greater import competition is found to explain part of the growing wage gap, consistent with Stolper–Samuelson effects. Point estimates suggest that these effects increased slightly over the period of study and are strongest in Quebec, Ontario, and British Columbia, provinces with the highest low-income-country import-penetration rates. However, the results also suggest (i) the relative wage effects of increased import competition are not as ‘clear cut’ as predicted by the Stolper–Samuelson theorem and (ii) that other individual and plant-level factors are important determinants of the structure of earnings inequality in Canada.
The Politics of Inequality in Globalizing Cities: How the Middle Classes Matter in the Governing of Buenos Aires
Authors: Kanai J Miguel
Published: August 2010

This paper contributes to the literature on the new politics of social inclusion and spatial justice in globalizing cities. My main argument is that accounts of such politics should focus on the multiple intervening social actors without neglecting or assuming the roles played by the urban middle classes. Focusing on the case of the City of Buenos Aires (CBA) after Argentina's neoliberal crisis of 2001, I show the importance of mobilized middle-class social actors in shaping institutional and territorial outcomes in a globalizing city that is highly polarized and fragmented. This study is based on participant observation, in-depth interviews, and archival research focused on (a) subscribers of state-sponsored citizen participation processes and (b) neighborhood activists with middle-class profiles—middle incomes, relative housing stability, and residency in neighborhoods with middle levels of development. Findings show that, although middle-class politics in the city evidenced a primary concern with place, neighborhood, and local territories, mobilized actors were also responding to deeper transformations brought about by processes of neoliberal globalization. Their repertoires of collective action also moved beyond the local scale and had significance for the wider governing of the city. Finally, it is shown that middle-class politics in the postcrisis CBA departed from the exclusionary attitudes evidenced in studies of other cities, which leads to the question of how such politics may be reconciled into broader coalitions seeking more egalitarian forms of urban globalization. Further inquiries for comparative analysis beyond the CBA are suggested in the paper's conclusion.
Mobilizing Cookstoves for Development: A Dual Adoption Framework Analysis of Collaborative Technology Innovations in Western India
Authors: Simon Gregory L
Published: August 2010

Domestic cookstoves in rural India have long been targeted by development programs dedicated to solving a diverse range of problems from deforestation and indoor air pollution to global warming and rural market inefficiencies. Theories on how technologies are mobilized in these design and diffusion innovation projects and what this presages for development outcomes can be improved by explicitly detailing the composition and structure of program governance frameworks. I develop a ‘dual adoption analytic framework’ to interrogate two technology innovation programs in Western India. This framework underscores the collaborative nature of technology mobilizations and, more specifically, how power is distributed across partnerships at different stages of the development process. Local partners are shown to function as influential mediating agents operating between extrinsic agencies and targeted village groups. They reinforce funding agency planning commitments while also activating economic contingencies and generating alternative development pathways. I also reveal how the structure of technology innovation projects—as either administratively heavy handed or committed to free market principles—influences intermediary behavior, intrapartnership structures of control and, ultimately, development outcomes for targeted artisan communities and households.
Food waste within food supply chains: quantification and potential for change to 2050
Authors: Parfitt Julian , Barthel Mark , Macnaughton Sarah
Published: August 2010

Food waste in the global food supply chain is reviewed in relation to the prospects for feeding a population of nine billion by 2050. Different definitions of food waste with respect to the complexities of food supply chains (FSCs)are discussed. An international literature review found a dearth of data on food waste and estimates varied widely; those for post-harvest losses of grain in developing countries might be overestimated. As much of the post-harvest loss data for developing countries was collected over 30 years ago, current global losses cannot be quantified. A significant gap exists in the understanding of the food waste implications of the rapid development of ‘BRIC’ economies. The limited data suggest that losses are much higher at the immediate post-harvest stages in developing countries and higher for perishable foods across industrialized and developing economies alike. For affluent economies, post-consumer food waste accounts for the greatest overall losses. To supplement the fragmentary picture and to gain a forward view, interviews were conducted with international FSC experts. The analyses highlighted the scale of the problem, the scope for improved system efficiencies and the challenges of affecting behavioural change to reduce post-consumer waste in affluent populations.
Food price volatility
Authors: Gilbert C. L. , Morgan C. W.
Published: August 2010

The high food prices experienced over recent years have led to the widespread view that food price volatility has increased. However, volatility has generally been lower over the two most recent decades than previously. Variability over the most recent period has been high but, with the important exception of rice, not out of line with historical experience. There is weak evidence that grains price volatility more generally may be increasing but it is too early to say.
Agricultural R&D, technology and productivity
Authors: Piesse J. , Thirtle C.
Published: August 2010

The relationships between basic and applied agricultural R&D, developed and developing country R&D and between R&D, extension, technology and productivity growth are outlined. The declining growth rates of public R&D expenditures are related to output growth and crop yields, where growth rates have also fallen, especially in the developed countries. However, growth in output value per hectare has not declined in the developing countries and labour productivity growth has increased except in the EU. Total factor productivity has generally increased, however it is measured. The public sector share of R&D expenditures has fallen and there has been rapid concentration in the private sector, where six multinationals now dominate. These companies are accumulating intellectual property to an extent that the public and international institutions are disadvantaged. This represents a threat to the global commons in agricultural technology on which the green revolution has depended. Estimates of the increased R&D expenditures needed to feed 9 billion people by 2050 and how these should be targeted, especially by the Consultative Group on International Agricultural Research (CGIAR), show that the amounts are feasible and that targeting sub-Saharan Africa (SSA) and South Asia can best increase output growth and reduce poverty. Lack of income growth in SSA is seen as the most insoluble problem.
Ecosystem services and agriculture: tradeoffs and synergies
Authors: Power Alison G.
Published: August 2010

Agricultural ecosystems provide humans with food, forage, bioenergy and pharmaceuticals and are essential to human wellbeing. These systems rely on ecosystem services provided by natural ecosystems, including pollination, biological pest control, maintenance of soil structure and fertility, nutrient cycling and hydrological services. Preliminary assessments indicate that the value of these ecosystem services to agriculture is enormous and often underappreciated. Agroecosystems also produce a variety of ecosystem services, such as regulation of soil and water quality, carbon sequestration, support for biodiversity and cultural services. Depending on management practices, agriculture can also be the source of numerous disservices, including loss of wildlife habitat, nutrient runoff, sedimentation of waterways, greenhouse gas emissions, and pesticide poisoning of humans and non-target species. The tradeoffs that may occur between provisioning services and other ecosystem services and disservices should be evaluated in terms of spatial scale, temporal scale and reversibility. As more effective methods for valuing ecosystem services become available, the potential for ‘win–win’ scenarios increases. Under all scenarios, appropriate agricultural management practices are critical to realizing the benefits of ecosystem services and reducing disservices from agricultural activities.
Energy and the food system
Authors: Woods Jeremy , Williams Adrian , Hughes John K. , Black Mairi , Murphy Richard
Published: August 2010

Modern agriculture is heavily dependent on fossil resources. Both direct energy use for crop management and indirect energy use for fertilizers, pesticides and machinery production have contributed to the major increases in food production seen since the 1960s. However, the relationship between energy inputs and yields is not linear. Low-energy inputs can lead to lower yields and perversely to higher energy demands per tonne of harvested product. At the other extreme, increasing energy inputs can lead to ever-smaller yield gains. Although fossil fuels remain the dominant source of energy for agriculture, the mix of fuels used differs owing to the different fertilization and cultivation requirements of individual crops. Nitrogen fertilizer production uses large amounts of natural gas and some coal, and can account for more than 50 per cent of total energy use in commercial agriculture. Oil accounts for between 30 and 75 per cent of energy inputs of UK agriculture, depending on the cropping system. While agriculture remains dependent on fossil sources of energy, food prices will couple to fossil energy prices and food production will remain a significant contributor to anthropogenic greenhouse gas emissions. Technological developments, changes in crop management, and renewable energy will all play important roles in increasing the energy efficiency of agriculture and reducing its reliance of fossil resources.
Expanded roles of the Fanconi anemia pathway in preserving genomic stability
Authors: Kee Younghoon , D'Andrea Alan D.
Published: August 2010

Studying rare human genetic diseases often leads to a better understanding of normal cellular functions. Fanconi anemia (FA), for example, has elucidated a novel DNA repair mechanism required for maintaining genomic stability and preventing cancer. The FA pathway, an essential tumor-suppressive pathway, is required for protecting the human genome from a specific type of DNA damage; namely, DNA interstrand cross-links (ICLs). In this review, we discuss the recent progress in the study of the FA pathway, such as the identification of new FANCM-binding partners and the identification of RAD51C and FAN1 (Fanconi-associated nuclease 1) as new FA pathway-related proteins. We also focus on the role of the FA pathway as a potential regulator of DNA repair choices in response to double-strand breaks, and its novel functions during the mitotic phase of the cell cycle.
Merlin in organ size control and tumorigenesis: Hippo versus EGFR?
Authors: Yi Chunling , Kissil Joseph L.
Published: August 2010

The role of the NF2 gene as a tumor suppressor has been well established. In this issue of Genes & Development, Benhamouche and colleagues (pp. 1718–1730) demonstrate that NF2 is also involved in the regulation of organ size control in mammals. Conditional knockout of Nf2 in the mouse liver results in massive organ enlargement and eventual tumor development, which is attributed to the specific expansion of oval cells. Here we discuss these findings and the proposed molecular mechanisms involved within the context of our current understanding of the pathways regulated by NF2.
Tbr2-positive intermediate (basal) neuronal progenitors safeguard cerebral cortex expansion by controlling amplification of pallial glutamatergic neurons and attraction of subpallial GABAergic interneurons
Authors: Sessa Alessandro , Mao Chai-An , Colasante Gaia , Nini Alessandro , Klein William H. , Broccoli Vania
Published: August 2010

Little is known about how, during its formidable expansion in development and evolution, the cerebral cortex is able to maintain the correct balance between excitatory and inhibitory neurons. In fact, while the former are born within the cortical primordium, the latter originate outward in the ventral pallium. Therefore, it remains to be addressed how these two neuronal populations might coordinate their relative amounts in order to build a functional cortical network. Here, we show that Tbr2-positive cortical intermediate (basal) neuronal progenitors (INPs) dictate the migratory route and control the amount of subpallial GABAergic interneurons in the subventricular zone (SVZ) through a non-cell-autonomous mechanism. In fact, Tbr2 interneuron attractive activity is moderated by Cxcl12 chemokine signaling, whose forced expression in the Tbr2 mutants can rescue, to some extent, SVZ cell migration. We thus propose that INPs are able to control simultaneously the increase of glutamatergic and GABAergic neuronal pools, thereby creating a simple way to intrinsically balance their relative accumulation.
Carl Gustav before he became Jung
Authors: Grivet‐Shillito Marie‐Laure
Published: August 2010

It was not until 1983 that Jung's first texts were published in London as The Zofingia Lectures. Not translated into French, The Zofingia Lectures are still not available to the French‐speaking public. This delay is due to an oversight: tucked away in a drawer, these texts were only discovered after Jung's death. There are five lectures that were given between 28 November 1896 and 7 January 1899. Although written when young – Carl was twenty‐one when he delivered the first lecture – they are worthy of interest. These lectures outline the major aspects of his subsequent work and reveal what we can call Carl's psychic wound and the tremendous energy that he drew on to survive.

However, without reading between the lines and without subjecting Jung to psychoanalytical interpretations, the author attempts to link the dynamics of these first works to certain autobiographical or epistolary confidences. This wound or Carl's father complex and the resulting deprivation are clearly mapped out here.