bluuebunny/crossref_metadata_2025 huggingface dataset:
Le pilotage par l’État de la formation des enseignants du début des années 1990 à nos jours et ses incidences sur le métier de formateur
Authors: Lapostolle Guy , Grisoni Pascal , Solomon Tsehaye Rachel
Published: February 2014

L’objet de cet article est de questionner, dans une perspective historique, la manière dont l’État a organisé et a fait évoluer la formation des enseignants du début des années 1990 à nos jours. Il s’attache à mettre en lumière les ambitions qui ont présidé aux réformes et tente de montrer la manière dont le métier de formateur d’enseignants s’est constitué et a évolué. Le formateur avait acquis un certain nombre de savoir-faire, et plus généralement une certaine culture, qui pourraient conduire à affirmer qu’un processus de professionnalisation était en cours, et ce jusqu’au milieu des années 2000. Ce processus tendait à rassembler sous une même dénomination, celle de « formateur », des intervenants dans la formation des enseignants, de statuts, d’origines et de compétences diverses. Cette consolidation du métier s’appuyait en partie sur un certain nombre de ruptures, notamment par rapport aux caractéristiques du métier d’enseignant. La masterisation fera voler en éclat ce processus. Il s’agira de tenter d’appréhender les conséquences de cette réforme sur le (s) métier (s) de formateur.
L’accompagnement dans la professionnalisation du métier d’enseignant. Le point de vue des formateurs
Authors: Loizon Denis , Charvy Nathalie , Cartierre Nathalie
Published: February 2014

La recherche présentée s’intéresse plus particulièrement à un aspect particulier de la professionnalisation : l’accompagnement. Dans les déclarations des formateurs en IUFM, nous avons identifié cinq dimensions de l’accompagnement en relation avec le rapport au savoir : rapport à l’institution, à l’autre, à sa pratique, aux savoirs et à l’expérience antérieure. Si cette dernière dimension revêt un caractère important dans les choix et les pratiques d’accompagnement, nos résultats montrent que les définitions de l’accompagnement sont hétérogènes avec des modalités de mises en oeuvre différentes selon les sujets qui s’appuient bien souvent sur les expériences professionnelles antérieures à la masterisation. Néanmoins, nous avons pu constater des adaptations dans le cadre des masters, notamment l’accompagnement dans les groupes de références.
La formation des bénévoles : une démarche de professionnalisation ?
Authors: Tardif Bourgoin Florence
Published: February 2014

Les exigences de professionnalisation dans le champ de l’action sociale préoccupent les associations dans un contexte de réduction des financements. Les référentiels de compétences accompagnent ainsi le recrutement des professionnels et les tendances à la sélection des bénévoles ainsi que la formulation d’objectifs en vue de leur qualification. Dans un contexte d’éducation populaire (par exemple dans les centres sociaux) favorisant la transmission des savoirs et des expériences dans un objectif de construction partagée, quelles places occupent la formation et la professionnalisation des bénévoles ?
Se professionnaliser dans un dispositif de formation spécialisée
Authors: Troncin Thierry
Published: February 2014

Les nouvelles modalités de scolarisation des élèves handicapés interrogent les enseignants dans l’exercice de leur métier, en particulier ceux qui sont confrontés aux inscrits dans les troubles importants des fonctions cognitives. Les dispositifs de formation et d’accompagnement aident à identifier les compétences constitutives d’une nouvelle identité professionnelle enseignante et contribuent à initier et à enrichir ce processus de transformation identitaire. L’analyse des regards portés par les enseignants inscrits en formation spécialisée par alternance permet de mieux cerner les conditions requises afin que les leviers de transformation des postures et des pratiques professionnelles se manifestent.
Effects of postdeposition annealing on the metal–insulator transition of VO2−
x thin films prepared by RF magnetron sputtering
Authors: Liu Shiu-Jen , Su Yu-Tai , Hsieh Juang-Hsin
Published: February 2014

We report the fabrication of textured VO2−

x
films on c-cut sapphire substrates by postdeposition annealing of V2O3 films prepared by RF magnetron sputtering using V2O3 as the target. Although the prepared VO2−

x
films are expected to be oxygen-deficient, overoxidation on the film surface was revealed by X-ray photoelectron spectroscopy. The metal–insulator transition (MIT) characteristics of the VO2−

x
films were investigated. MIT parameters including the transition temperature, transition sharpness, and hysteresis width of the VO2−

x
films were manipulated by varying the oxygen pressure during postdeposition annealing. The suppression of optical transmittance in the near-infrared region was observed by increasing the temperature through the MIT.
A novel high-density embedded AND-type split gate flash memory
Authors: Shen Wen Chao , Wang Ching-Hua , Pan Hsin-Wei , Yang Zhi-Sung , Chih Yue Der , Lee Te-Liang , Lien Chiu-Wang , King Ya-Chin , Lin Chrong Jung
Published: February 2014

A new high-density AND-type split gate (ASG) flash memory realized by the Taiwan Semiconductor Manufacturing Company (TSMC) 0.18 µm embedded flash process has been successfully demonstrated and fabricated. This ASG flash memory has a pair of symmetric floating gates for performance of 2 bits/cell. By device and process optimization, this cell can operate via highly efficient source side injection (SSI) and Fowler–Nordheim (FN) tunneling mechanisms for program and erase, respectively. Moreover, ASG flash memory significantly shrinks 50% of the unit cell size by sharing word line (WL) and eliminating bit line (BL) contact. Since the ASG flash memory cell and process used are inherited from proven split-gate technology, this work also provides a highly reliable solution for high-density embedded flash application.
Intracardiac Echocardiography
Authors: George Jon C. , Varghese Vincent , Mogtader Allen
Published: February 2014

Intracardiac echocardiography (ICE) uses a catheter‐based steerable ultrasound probe that is passed into the right heart chambers to image intracardiac structures. The transducer can be variably positioned for optimal imaging: in the inferior vena cava to visualize the abdominal aorta; in the right atrium for the interatrial septum, aortic, mitral, and tricuspid valves, and pulmonary veins; or in the right ventricle for the left ventricular function, outflow tract, or pulmonary artery. Intracardiac echocardiography is primarily used for imaging during an invasive cardiac procedure using conscious sedation, when transthoracic image quality would likely be inadequate, and transesophageal imaging would require general anesthesia. Intracardiac echocardiography is generally well tolerated and provides adequate images and sufficient information for the procedure performed. In the cardiac catheterization laboratory, ICE is routinely used for patent foramen ovale, atrial septal defect, and ventricular septal defect closures, allowing adequate percutaneous placement of septal occluders. It is now being considered in the current era of transcatheter aortic valve implantation necessitating improved imaging approaches for accurate placement. It is also routinely used for trans‐septal punctures during mitral valvuloplasty and, more recently, with the advent of left atrial appendage closure devices. This article provides a comprehensive review of the current technology for ICE and its growing applications in the realm of interventional cardiology.
Prediction of Maximal Surface Electromyographically Based Voluntary Contractions of Erector Spinae Muscles From Sonographic Measurements During Isometric Contractions
Authors: Cuesta-Vargas Antonio I. , González-Sánchez Manuel
Published: February 2014

Objectives

Currently, there are no studies combining electromyography (EMG) and sonography to estimate the absolute and relative strength values of erector spinae (ES) muscles in healthy individuals. The purpose of this study was to establish whether the maximum voluntary contraction (MVC) of the ES during isometric contractions could be predicted from the changes in surface EMG as well as in fiber pennation and thickness as measured by sonography.

Methods

Thirty healthy adults performed 3 isometric extensions at 45° from the vertical to calculate the MVC force. Contractions at 33% and 100% of the MVC force were then used during sonographic and EMG recordings. These measurements were used to observe the architecture and function of the muscles during contraction. Statistical analysis was performed using bivariate regression and regression equations.

Results

The slope for each regression equation was statistically significant (P < .001) with R2 values of 0.837 and 0.986 for the right and left ES, respectively. The standard error estimate between the sonographic measurements and the regression‐estimated pennation angles for the right and left ES were 0.10 and 0.02, respectively.

Conclusions

Erector spinae muscle activation can be predicted from the changes in fiber pennation during isometric contractions at 33% and 100% of the MVC force. These findings could be essential for developing a regression equation that could estimate the level of muscle activation from changes in the muscle architecture.
Distribution Pattern of Sonographically Guided Iliopsoas Injections
Authors: Dauffenbach Jason , Pingree Matthew J. , Wisniewski Steve J. , Murthy Naveen , Smith Jay
Published: February 2014

Objectives

To investigate the distribution pattern of sonographically guided iliopsoas (IP) injections in an unembalmed cadaveric model.

Methods

A single experienced operator completed 10 sonographically guided IP injections in 5 unembalmed cadaveric pelvic specimens (4 male and 1 female; ages 55–95 years; body mass indices, 15.5–27.5 kg/m2) using a previously described in‐plane, lateral‐to‐medial approach short axis to the tendon. Each injection consisted of 7 mL of a 20% dilution of contrast material injected between the IP tendon and the acetabular rim using a 22‐gauge, 87.5‐mm (3½‐in) needle. To facilitate interpretation of contrast patterns, 2 additional injections were performed on single hips: sonographically guided 14 mL contrast‐latex IP injection and sonographically guided superficial IP “peritendinous” injection with 7 mL of contrast‐latex. Immediately before and after each injection, fluoroscopic images were obtained with a fixed C‐arm equipped with coned beam computed tomography. After each injection, radiographic images were evaluated by a board‐certified, fellowship‐trained musculoskeletal radiologist to determine injectate distribution. Specimens receiving contrast‐latex injections were dissected 48 hours after injection to determine the anatomic location of the injectate.

Results

Nine of 10 IP injections (90%) produced characteristic “U‐shaped” flow patterns covering 50% to nearly 100% of the IP tendon circumference and resembling previously published IP bursograms. One injection was excluded because the majority of the latex was within the pectineus muscle, likely due to technical factors. Latex flowed an average of 5.3 cm (range, 0.3–7.9 cm) cephalad and 5.2 cm (range, 1.0–7.5 cm) caudad to the acetabular rim. The large‐volume (14‐mL) IP injection produced a similar flow pattern to the 7 mL injections, whereas the superficial peritendinous injection produced a contrast pattern consistent with intramuscular flow. Subsequent dissection confirmed bursal flow for the 14‐mL injection, whereas the superficial peritendinous injection placed latex within the superficial portion of the IP muscle (ie, intramuscular).

Conclusions

Sonographically guided IP injections using an in‐plane, lateral‐to‐medial technique place injectate into the IP bursa between the IP tendon and the acetabular rim. Within the limits of this cadaveric investigation, this sonographically guided 7‐mL IP “bursa” injection may provide a minimum of 50% circumferential IP tendon coverage and approximately 5 cm of cephalad and caudad flow. There does not appear to be a peritendinous space deep to the IP tendon at the acetabular rim that is both outside the bursa and amenable to sonographically guided injection. Injections into the superficial aspect of the IP using 7‐mL volumes may not deliver injectate deep to the IP tendon and therefore may represent a fundamentally different injection.
Simple and Complex Fibroadenomas
Authors: Pinto Joana , Aguiar Ana Teresa , Duarte Hálio , Vilaverde Filipa , Rodrigues Ângelo , Krug José Luís
Published: February 2014

Objectives

Complex fibroadenomas are fibroadenomas harboring 1 or more complex pathologic features: epithelial calcifications, apocrine metaplasia, sclerosing adenosis, and cysts larger than 3 mm. No sonographic features have been clearly defined for the distinction of simple fibroadenomas from complex ones, which are associated with an increased cancer risk. We aimed to evaluate the accuracy of sonographic features for the prediction of complexity in fibroadenomas.

Methods

A total of 252 fibroadenomas were found at consecutive percutaneous needle or excisional surgical biopsy. Sixty‐three were excluded because their respective imaging examinations were not recorded on digital support and consequently were not available. According to histologic diagnoses, fibroadenomas (n = 189) were classified into simple (n = 159) and complex (n = 30). The size, number, and sonographic features were assessed, and their respective accuracy rates for prediction of complexity were analyzed.

Results

All patients were women. Complex fibroadenomas presented more frequently as solitary nodules (n = 21 [70%]) and were significantly larger than simple fibroadenomas (1.9 versus 1.3 cm; P = .009). Image predictors of complexity were an irregular shape (P< .001), noncircumscribed contours (indistinct, angular, microlobulated, or spiculated; P < .001), a complex echo structure (P < .001), the presence of microcalcifications (P = .002), and posterior acoustic enhancement (P < .001). By logistic multivariate regression, a complex echo structure (odds ratio [OR], 9.5; 95% confidence interval [CI], 2.8–32.3), noncircumscribed contours (OR, 3.7; 95% CI, 1.1–12.8), and posterior acoustic enhancement (OR, 4.0; 95% CI, 1.1–14.6) were independent predictors of complexity. Receiver operating characteristic curve analysis showed that a complex echo structure was the most accurate sonographic finding for identification of complex fibroadenomas (area under the curve, 0.74).

Conclusions

Certain sonographic features are associated with complex fibroadenomas and can help the radiologist decide which ones require biopsy.
Reproducibility of Renal Volume Measurement in Adults Using 3‐Dimensional Sonography
Authors: de Amorim Paiva Camila Caroline , de Mello Junior Carlos Fernando , Guimarães Filho Helio Antonio , de Brito Gomes Camila Albuquerque , Junior Lusimário Rodrigues Silva , Junior Gilberto Moura Brito , Paiva Cláudio Sérgio Medeiros
Published: February 2014

Objectives

The purpose of this study was to determine the interobserver reproducibility of renal volume measurement performed by 3‐dimensional (3D) sonography.

Methods

We conducted an exploratory, quantitative, observational, and descriptive cross‐sectional study. We calculated ranges, means, and standard deviations of the renal volumes obtained with 3D sonography by 2 different examiners from a sample of 30 patients. The interobserver reproducibility was assessed by calculating intraclass correlation coefficients (ICCs) and by construction of Bland‐Altman plots.

Results

The ICC between the right 3D renal volumes obtained by examiners 1 and 2 was 0.8552 (95% confidence interval, 0.7153–0.9292), showing excellent reproducibility (P < .0001). For the left 3D renal volumes obtained by examiners 1 and 2, the ICC was 0.6411 (95% confidence interval, 0.3652–0.8135), showing average to good reproducibility (P = .0001). The Bland‐Altman plots showed mean differences ± SD of −4.8% ± 23.9% between the right renal volumes obtained by examiners 1 and 2 and −2.2% ± 38% between the left renal volumes. The 95% limits of agreement between the right renal volumes obtained by examiners 1 and 2 were −28.7% to 19%, whereas those between the left renal volumes were −40.2% to 35.7%.

Conclusions

Three‐dimensional sonography showed good interobserver reproducibility, which was better for the right kidney. It appears necessary to establish standardized techniques for acquisition of sonographic renal volumes.
Shear Wave Elastography for Liver Stiffness Measurement in Clinical Sonographic Examinations
Authors: Yoon Jeong Hee , Lee Jeong Min , Han Joon Koo , Cho Byung Ihn
Published: February 2014

Objectives

The purpose of this study was to determine the optimal minimum number of liver stiffness measurements on shear wave elastography (SWE) and to evaluate the frequency of technical failures and unreliable stiffness measurements and the intraobserver reproducibility of SWE.

Methods

This retrospective study was approved by our Institutional Review Board, and informed consent was waived. From August 2011 to January 2013, 540 patients underwent abdominal sonography, including SWE. In 86 patients (group 1), the minimum number of examinations was determined by comparing the intraclass correlation coefficient (ICC) of subsets of the first 2 to 14 measurements with that from 15 measurements. In 454 patients (group 2), 2 SWE sessions were performed in the right lobe within 1 day. Technical failure was defined as when no or little signal was obtained in the elastogram during the first 5 acquisitions; unreliable SWE results were defined as when the interquartile range/median liver stiffness value exceeded 30%. Intraobserver reproducibility was assessed using ICCs and Bland‐Altman plots.

Results

In group 1, the ICCs did not significantly increase after the first 6 measurements. In group 2, there were technical failures and unreliable results in 47 patients (10.35%) and 74 patients (16.29%), respectively. In 407 patients, after excluding technical failures, there was no significant difference in the median liver stiffness values between the 2 sessions (6.95 versus 6.86 kPa; P > .05). The overall intraobserver reproducibility was excellent (ICC, 0.95).

Conclusions

In this study, the optimal minimum number of SWE measurements was 6, and SWE using 6 measurements showed excellent intraobserver reproducibility.
Three‐Dimensional Sonographic Assessment of Placental Volume and Vascularization in Pregnancies Complicated by Hypertensive Disorders
Authors: de Almeida Pimenta Eduardo Jorge , Silva de Paula Carla Fagundes , Duarte Bonini Campos Juliana Alvares , Fox Karin Anneliese , Francisco Rossana , Ruano Rodrigo , Zugaib Marcelo
Published: February 2014

Objectives

The purpose of this study was to evaluate the association between placental volumes, placental vascularity, and hypertensive disorders in pregnancy.

Methods

A prospective case‐control study was conducted between April 2011 and July 2012. Placental volumes and vascularity were evaluated by 3‐dimensional sonographic, 3‐dimensional power Doppler histographic, and 2‐dimensional color Doppler studies. Pregnant women were classified as normotensive or hypertensive and stratified by the nature of their hypertensive disorders. The following variables were evaluated: observed‐to‐expected placental volume ratio, placental volume‐to‐estimated fetal weight ratio, placental vascular indices, and pulsatility indices of the right and left uterine and umbilical arteries.

Results

Sixty‐six healthy pregnant women and 62 pregnant women with hypertensive disorders were evaluated (matched by maternal age, gestational age at sonography, and parity). Placental volumes were not reduced in pregnancy in women with hypertensive disorders (P > .05). Conversely, reduced placental vascularization indices (vascularization index and vascularization‐flow index) were observed in pregnancies complicated by hypertensive disorders (P < .01; P < .01), especially in patients with superimposed preeclampsia (P = .04; P = .02). A weak correlation was observed between placental volumes, placental vascular indices, and Doppler studies of the uterine and umbilical arteries.

Conclusions

Pregnancies complicated by hypertensive disorders are associated with reduced placental vascularity but not with reduced placental volumes. These findings are independent of changes in uterine artery Doppler studies. Future studies of the prediction of preeclampsia may focus on placental vascularity in combination with results of Doppler studies of the uterine arteries.
Real‐time Ultrasound Elastography for Differentiation of Benign and Malignant Thyroid Nodules
Authors: Sun Jiasi , Cai Jingyu , Wang Xuemei
Published: February 2014

Objectives

The clinical challenge of managing thyroid nodules nowadays is to diagnose the minority of malignant disease. Real‐time ultrasound elastography, which can measure tissue elasticity, is used as a complement to conventional sonography for improving the diagnosis of thyroid tumors. There are 2 common criteria for evaluating an elastogram: the elasticity score and strain ratio. This meta‐analysis was performed to expand on a previous meta‐analysis to assess the diagnostic power of ultrasound elastography in differentiating benign and malignant thyroid nodules for elasticity score and strain ratio assessment.

Methods

The MEDLINE, EMBASE, PubMed, and Cochrane Library databases up to January 31, 2013, were searched. The pooled sensitivity, specificity, and summary receiver operating characteristic curve were obtained from individual studies with a random‐effects model. The extent and sources of heterogeneity were explored.

Results

A total of 5481 nodules in 4468 patients for elasticity score studies and 1063 nodules in 983 patients for strain ratio studies were analyzed. The overall mean sensitivity and specificity of ultrasound elastography for differentiation of thyroid nodules were 0.79 (95% confidence interval [CI], 0.77–0.81) and 0.77 (95% CI, 0.76–0.79) for elasticity score assessment and 0.85 (95% CI, 0.81–0.89) and 0.80 (95% CI, 0.77–0.83) for strain ratio assessment, respectively. The areas under the curve for the elasticity score and strain ratio were 0.8941 and 0.9285.

Conclusions

These results confirmed those obtained in the previous meta‐analysis. Ultrasound elastography has high sensitivity and specificity for identification of thyroid nodules. It is a promising tool for reducing unnecessary fine‐needle‐aspiration biopsy.
Three‐Dimensional Endovaginal Sonography of Synthetic Implanted Materials in the Female Pelvic Floor
Authors: Denson Lindsay , Shobeiri S. Abbas
Published: February 2014

The objective of this pictorial essay is to emphasize the ability of 3‐dimensional endovaginal sonography to image synthetic implanted materials in the female pelvic floor. Implanted materials discussed in this pictorial essay include polypropylene vaginal mesh, polypropylene suburethral slings, and urethral bulking agents. Three‐dimensional endovaginal sonography allows for more detailed imaging compared to computed tomography and magnetic resonance imaging of the female pelvic floor, in that each plane can be manipulated to show unique images of synthetic implanted materials.
Storm time enhancements of 630.0 nm airglow associated with polar cap patches
Authors: Sakai J. , Hosokawa K. , Taguchi S. , Ogawa Y.
Published: February 2014

We examined the brightness of 630.0 nm airglow, I630, associated with polar cap patches observed during a magnetic storm that occurred on 22 January 2012. Brightness was measured using an all‐sky imager (ASI) located at Longyearbyen, Svalbard. The observed I630 was compared with the F region electron density observed by the European Incoherent Scatter Svalbard Radar (ESR). The I630 was positively correlated with the F2 layer peak electron density, NmF2, and inversely correlated with the altitude of the F2layer peak electron density, hmF2, as expected from the known relationship between these parameters. To estimate the altitude of the peak emission of the airglow, we performed model calculations of the volume emission rate, V630, under quiet and disturbed conditions, using Mass Spectrometer Incoherent Scatter modeled neutral gas profiles and the electron density profile obtained from the ESR data. In order to validate the V630 calculation, I630 was calculated by integrating the V630 along altitude and then compared with the ASI‐observed I630. During the observation periods the measured brightness frequently exceeded the calculated I630; we infer that in most cases, low‐energy particle precipitation is responsible for the extra brightness. However, when there was less particle precipitation, the observed values were in good agreement with the calculated values. Under the magnetically disturbed conditions during our observations, the model calculation showed that the altitude of V630 peak increases, the thickness of the emission layer increases, and patch brightness increases.
Generation of ion cyclotron waves in the corona and solar wind
Authors: Omidi N. , Isenberg P. , Russell C. T. , Jian L. K. , Wei H. Y.
Published: February 2014

To examine the generation and nonlinear evolution of ion cyclotron waves in the corona and solar wind, we perform electromagnetic simulations using a wide range of plasma conditions and ion velocity distribution functions. The source of the instability is temperature anisotropy of ions with temperature perpendicular to the magnetic field larger than parallel. For velocity distribution we use Maxwellian, bi‐Maxwellian, and Fermi‐accelerated functions with perpendicular temperature larger than parallel with the aim to understand the extent to which the details of the distribution function impact the general properties and the nonlinear evolution of the instability. The results show that in a proton‐electron plasma, ion cyclotron waves are generated over a wide range of temperature anisotropies and plasma beta. Also, the general properties of the instability and the nonlinear evolution of the waves are not sensitive to the details of the velocity distribution functions. Allowing for the presence of minor ion species we show that these ions by themselves can drive the instability and generate waves with frequencies below the gyrofrequency of the minor ions. In the event that protons also have temperature anisotropy, waves on the proton branch are also generated. Results using bi‐Maxwellian or Fermi‐accelerated velocity distribution functions show similar properties for the instability and the nonlinear evolution of the waves. However, differences are found when allowing for relative drifts between the protons and minor ions in that when using Fermi‐accelerated distribution functions oblique ion cyclotron waves are generated that are not observed in simulations using bi‐Maxwellian distribution function.
Bimodal size of Jupiter's magnetosphere
Authors: McComas D. J. , Bagenal F. , Ebert R. W.
Published: February 2014

Observations of Jovian magnetopause crossing by a number of different spacecraft have established that Jupiter's magnetosphere has a generally bimodal size distribution, with typical standoff distances at the nose of ~63 and ~92 RJ. Here we examine both the external solar wind structure and time constants and the internal magnetospheric time constants for shedding and refilling material in the Jovian plasma disk. We show that these latter time constants are ~ hours to ~10 h, comparable to the compression time of the magnetopause, but shorter than the typically several day expansion time when the solar wind dynamic pressure decreases. Together, we show that it is the well‐developed compressions and rarefactions in the solar wind at ~5 AU that produced the generally bimodally structured solar wind dynamic pressure and hence Jovian magnetospheric size.
Impacts of vertically propagating tides on the mean state of the ionosphere‐thermosphere system
Authors: Jones M. , Forbes J. M. , Hagan M. E. , Maute A.
Published: February 2014

The National Center for Atmospheric Research Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (TIE‐GCM) is utilized to understand the role that upward propagating tides play in determining the zonal mean state of the ionosphere‐thermosphere system. A sensitivity assessment of the TIE‐GCM shows that TIE‐GCM solutions greatly depend on the lower boundary conditions. We also establish the veracity of our TIE‐GCM solutions within and above the dynamo region. To isolate the mean effects of tidal dissipation, differences between TIE‐GCM simulations with and without lower boundary tidal forcing as specified by the Climatological Tidal Model of the Thermosphere are investigated. Dissipation of the DW1, (diurnal westward propagating tide with zonal wave number 1), diurnal eastward propagating tide with zonal wave number 3, and SW2 (semidiurnal tide with zonal wave number 2) explains most of ∼10–30 m s−1 seasonal and latitudinal variability in zonal winds within the dynamo region, with SW2 playing a greater role than ascribed in previous studies. Tidal dissipation at low latitudes causes a 9% decrease (30% increase) in [O] ([O2]) number densities near the F2 layer peak, leading to at least a 9% decrease in peak electron density (NmF2) throughout the year. F2 layer peak height (hmF2) differences of ‐4 to 2 km at low latitudes are explained by variations in the field‐aligned plasma motion driven by meridional wind differences induced by tidal dissipation. Compositional effects are mainly driven by DW1 and SW2, which differs from previous interpretations of tidal‐driven composition changes by DW1 “tidal mixing” exclusively. We suggest that tides may produce a net transport of constituents in the thermosphere similar to the way that, e.g., gravity waves can drive net transport of sodium in the mesosphere.
Transport from convective overshooting of the extratropical tropopause and the role of large‐scale lower stratosphere stability
Authors: Homeyer Cameron R. , Pan Laura L. , Barth Mary C.
Published: February 2014

Simulations of observed convective systems with the Advanced Research Weather Research and Forecasting (ARW‐WRF) model are used to test the influence of the large‐scale lower stratosphere stability environment on the vertical extent of convective overshooting and transport above the extratropical tropopause. Three unique environments are identified (double tropopause, stratospheric intrusion, and single tropopause), and representative cases with comparable magnitudes of convective available potential energy are selected for simulation. Convective injection into the extratropical lower stratosphere is found to be deepest for the double‐tropopause case (up to 4 km above the lapse‐rate tropopause) and at comparable altitudes for the remaining cases (up to 2 km above the lapse‐rate tropopause). All simulations show evidence of gravity wave breaking near the overshooting convective top, consistent with the identification of its role as a transport mechanism in previous studies. Simulations for the double‐tropopause case, however, also show evidence of direct mixing of the overshooting top into the lower stratosphere, which is responsible for the highest levels of injection in that case. In addition, the choice of bulk microphysical parameterization for ARW‐WRF simulations is found to have little impact on the transport characteristics for each case.
Paleomagnetic evidence for a post‐Eocene 90° CCW rotation of internal Apennine units: A linkage with Corsica‐Sardinia rotation?
Authors: Caricchi Chiara , Cifelli Francesca , Sagnotti Leonardo , Sani Federico , Speranza Fabio , Mattei Massimo
Published: February 2014

We report on an extensive paleomagnetic study (36 sites) of the Tuscan Nappe succession from the Northern Apennines Arc, aimed to reconstruct the tectonic evolution of the internal sector of this chain. We analyzed Eocene pelagic foreland ramp deposits (Scaglia Toscana Formation) and Oligocene–lower Miocene siliciclastic turbidites (Macigno and Falterona Formations). Paleomagnetic results show that the internal sector of the Northern Apennines underwent large counterclockwise (CCW) rotations with respect to the Adria‐Africa foreland. A decrease in the rotation magnitude was observed from the southern to the northern sector of the arc (from 91 to 36°). This trend is opposite to that observed in the more external units of Northern Apennines and demonstrates that the oroclinal bending model, which has been proposed for the external units of the chain, is not appropriate to explain the evolution of the internal sector of the arc. On the basis of the observed paleomagnetic pattern, we propose a new tectonic model in which the Tuscan and Falterona‐Cervarola units in the southern area were first rotated CCW along with the Corsica‐Sardinia block during its lower Miocene rotational drifting and were later involved in the main phases of rotational emplacement and translation toward the outermost sector (Umbria domain), thus yielding the final curved shape of the Northern Apennines chain. Data from this study represent the first paleomagnetic evidence of the influence of the Corsica‐Sardinia CCW rotation in the Apennines orogenic wedge deformation, in the general framework of the geodynamic evolution of the Central Mediterranean subduction system.
Adsorption and capillary condensation in porous media as a function of the chemical potential of water in carbon dioxide
Authors: Heath Jason E. , Bryan Charles R. , Matteo Edward N. , Dewers Thomas A. , Wang Yifeng , Sallaberry Cédric J.
Published: February 2014

The chemical potential of water may play an important role in adsorption and capillary condensation of water under multiphase conditions at geologic CO2 storage sites. Injection of large volumes of anhydrous CO2 will result in changing values of the chemical potential of water in the supercritical CO2 phase. We hypothesize that the chemical potential will at first reflect the low concentration of dissolved water in the dry CO2. As formation water dissolves into and is transported by the CO2 phase, the chemical potential of water will increase. We present a pore‐scale model of the CO2‐water interface or menisci configuration based on the augmented Young‐Laplace equation, which combines adsorption on flat surfaces and capillary condensation in wedge‐shaped pores as a function of chemical potential of water. The results suggest that, at a given chemical potential for triangular and square pores, liquid water saturation will be less in the CO2‐water system under potential CO2 sequestration conditions relative to the air‐water vadose zone system. The difference derives from lower surface tension of the CO2‐water system and thinner liquid water films, important at pore sizes <1 × 10−6 m, relative to the air‐water system. Water movement due to capillary effects will likely be minimal in reservoir rocks, but still may be important in finer grained, clayey caprocks, where very small pores may retain water and draw water back into the system via adsorption and capillary condensation, if dry‐out and then rewetting were to occur.
Heat flux modifications related to climate‐induced warming of large European lakes
Authors: Fink Gabriel , Schmid Martin , Wahl Bernd , Wolf Thomas , Wüest Alfred
Published: February 2014

Within the last decades, the water temperature of several European lakes has risen. It is assumed that these temperature increases are due to a reconfiguration of the heat‐balance components. This study explores the dominant modifications of heat exchange with the atmosphere and their temporal evolutions. The objective is to identify the primary changes in heat fluxes and the sequence of events of the reconfiguration for the period 1984–2011. For this purpose, a model was applied to Lake Constance to estimate the contributions of the individual heat fluxes to the total heat balance. The results show that increasing absorption of solar radiation (+0.21 ± 0.13 W m−2 yr−1) and of longwave radiation (+0.25 ± 0.11 W m−2 yr−1) was responsible for the lake surface warming of 0.046 ± 0.011°C yr−1. Heat losses to the atmosphere by longwave emission (−0.24 ± 0.06 W m−2 yr−1) and by latent heat flux (−0.27 ± 0.12 W m−2 yr−1) have intensified in parallel due to higher lake surface temperatures. The heat budget is in a quasi‐steady state, whereas incoming solar radiation and the warmer atmosphere increased the lake surface temperature; the warmer surface emits more longwave radiation and more water is evaporated. At each level of the slowly increasing water temperature, the heat fluxes are balanced. The overall change of the total heat content, however, is relatively little. Although the cooling effect of inflowing rivers decreased, this contribution is also small.
The pace of East African monsoon evolution during the Holocene
Authors: Weldeab Syee , Menke Valerie , Schmiedl Gerhard
Published: February 2014

African monsoon precipitation experienced a dramatic change in the course of the Holocene. The pace with which the African monsoon shifted from a strong early to middle to a weak late Holocene is critical for our understanding of climate dynamics, hydroclimate‐vegetation interaction, and shifts of prehistoric human settlements, yet it is controversially debated. On the basis of planktonic foraminiferal Ba/Ca time series from the eastern Mediterranean Sea, here we present a proxy record of Nile River runoff that provides a spatially integrated measure of changes in East African monsoon (EAM) precipitation. The runoff record indicates a markedly gradual middle to late Holocene EAM transition that lasted over 3500 years. The timing and pace of runoff change parallels those of insolation and vegetation changes over the Nile basin, indicating orbitally forced variation of insolation as the main EAM forcing and the absence of a nonlinear precipitation‐vegetation feedback. A tight correspondence between a threshold level of Nile River runoff and the timing of occupation/abandonment of settlements suggests that along with climate changes in the eastern Sahara, the level of Nile River and intensity of summer floods were likely critical for the habitability of the Nile Valley (Egypt).
Enhancing the Infrared Photoresponse of Silicon by Controlling the Fermi Level Location within an Impurity Band
Authors: Simmons Christie B. , Akey Austin J. , Mailoa Jonathan P. , Recht Daniel , Aziz Michael J. , Buonassisi Tonio
Published: February 2014

Strong absorption of sub‐band gap radiation by an impurity band has recently been demonstrated in silicon supersaturated with chalcogen impurities. However, despite the enhanced absorption in this material, the transformation of infrared radiation into an electrical signal via extrinsic photoconductivity—the critical performance requirement for many optoelectronic applications—has only been reported at low temperature because thermal impurity ionization overwhelms photoionization at room temperature. Here, dopant compensation is used to manipulate the optical and electronic properties and thereby improve the room‐temperature infrared photoresponse. Silicon co‐doped with boron and sulfur is fabricated using ion implantation and nanosecond pulsed laser melting to achieve supersaturated sulfur concentrations and a matched boron distribution. The location of the Fermi level within the sulfur‐induced impurity band is controlled by tuning the acceptor‐to‐donor ratio, and through this dopant compensation, three orders of magnitude improvement in infrared detection at 1550 nm is demonstrated.
Promoting Fresh Produce: A Losing Battle?
Authors: McLaughlin Edward W. , Kaiser Harry M. , Rickard Bradley J.
Published: February 2014

Previous research indicates that returns to agricultural producers from generic promotion of their products are substantial. Yet, despite public policy interest in increasing consumption of fruits and vegetables, the United States produce industry has not embraced industry wide promotion. We conduct a survey to better understand stakeholder opinion of a proposed promotion program, and to examine how changes in program design might influence support. Econometric results indicate that support would increase if specific promotion examples were provided, if evidence of likely profitability was clear and if substantial government matching funds were available. Policy implications, including the importance of appropriate target audience and clear communication of program features, are suggested.
Genetic mutations in early‐onset Parkinson's disease Mexican patients: Molecular testing implications
Authors: Monroy‐Jaramillo Nancy , Guerrero‐Camacho Jorge Luis , Rodríguez‐Violante Mayela , Boll‐Woehrlen Marie‐Catherine , Yescas‐Gómez Petra , Alonso‐Vilatela María Elisa , López‐López Marisol
Published: February 2014

Mutations in PARK2, PINK1, and DJ‐1 have been associated with autosomal recessive early‐onset Parkinson's disease. Here, we report the prevalence of sequence and structural mutations in these three main recessive genes in Mexican Mestizo patients. The complete sequences of these three genes were analyzed by homo/heteroduplex DNA formation and direct sequencing; exon dosage was determined by multiplex ligation‐dependent probe amplification and real‐time PCR in 127 patients belonging to 122 families and 120 healthy Mexican Mestizo controls. All individuals had been previously screened for the three most common LRRK2 mutations. The presence of two mutations in compound heterozygous or homozygous genotypes was found in 16 unrelated patients, 10 had mutations in PARK2, six in PINK1, and none in DJ‐1. Two PARK2‐PINK1 and one PARK2‐LRRK2 digenic cases were observed. Novel mutations were identified in PARK2 and PINK1 genes, including PINK1 duplication for the first time. Exon dosage deletions were the most frequent mutations in PARK2 (mainly in exons 9 and 12), followed by those in PINK1. The high prevalence of heterozygous mutations in PARK2 (12.3%) and the novel heterozygous and homozygous point mutations in PINK1 observed in familial and sporadic cases from various states of Mexico support the concept that single heterozygous mutations in recessive Parkinson's disease genes play a pathogenic role. These data have important implications for genetic counseling of Mexican Mestizo patients with early‐onset Parkinson's disease. The presence of digenic inheritance underscores the importance of studying several genes in this disease. A step‐ordered strategy for molecular diagnosis is proposed. © 2014 Wiley Periodicals, Inc.
The return of the jedi: comparison of the outcomes of endolaser dacryocystorhinostomy and endonasal dacryocystorhinostomy
Authors: Zengin Mehmet Özgür , Eren Erdem
Published: February 2014

Background

External dacryocystorhinostomy (DCR) is considered to be the gold standard treatment of primary acquired nasolacrimal duct obstruction. A better understanding of the endoscopic anatomy of the lacrimal sac has increased the success rate of endonasal DCR. Laser DCR has become popular in recent years and has a success rate comparable with those of other endonasal techniques. The aim of this study was to compare the surgical results of endonasal DCR (EDCR) and endonasal laser DCR (ELDCR).

Methods

Fifty‐four patients treated with ELDCR and 42 patients treated with EDCR for nasolacrimal duct obstruction from 2009 to 2012 with at least 1.5 years of follow‐up were retrospectively enrolled in this comparative study. Lack of patient complaints and irrigation testing were used as subjective and objective assessment tools, respectively.

Results

Both groups were similar in terms of age and sex. ELDCR had a success rate of 85.2%, and EDCR had a success rate of 92.9%. The difference between the 2 procedures was not statistically significant. ELDCR had a significantly shorter operative time than did EDCR (16.9 vs 24.4 minutes, respectively; p < 0.001).

Conclusion

Endonasal procedures have the advantage of no scar formation and do not disturb the pumping mechanism of the lacrimal sac. Their success rates are comparable with those of external DCR. Surgery is quicker, and with use of a laser, even less time is spent in the operating room. In selected cases, ELDCR can be a good alternative method with a high success rate.
Synthesis of Highly Substituted 3‐Formylfurans by a Gold(I)‐Catalyzed Oxidation/1,2‐Alkynyl Migration/Cyclization Cascade
Authors: Wang Tao , Shi Shuai , Hansmann Max M. , Rettenmeier Eva , Rudolph Matthias , Hashmi A. Stephen K.
Published: February 2014

3‐Formylfuran derivatives are core structures of a variety of bioactive natural products. However, procedures for their preparation are still rare and generally inefficient in terms of atom economy: These methods require multiple steps or harsh reaction conditions and show selectivity problems. An efficient gold(I)‐catalyzed cascade reaction that leads to 3‐formylfurans from easily accessible starting materials is now described. A wide variety of 3‐formylfurans were obtained from the corresponding symmetric and unsymmetric 1,4‐diyn‐3‐ols in the presence of an N‐oxide in good to excellent yields. Isotope‐labeling experiments as well as DFT calculations support a mechanism in which, after an initial oxygen transfer, a 1,2‐alkynyl migration is favored over a hydride shift; a cyclization ensues to afford the desired functionalized furan core.
A Visualizable Chain‐Terminating Inhibitor of Glycosaminoglycan Biosynthesis in Developing Zebrafish
Authors: Beahm Brendan J. , Dehnert Karen W. , Derr Nicolas L. , Kuhn Joachim , Eberhart Johann K. , Spillmann Dorothe , Amacher Sharon L. , Bertozzi Carolyn R.
Published: February 2014

Heparan sulfate (HS) and chondroitin sulfate (CS) glycosaminoglycans (GAG) are proteoglycan‐associated polysaccharides with essential functions in animals. They have been studied extensively by genetic manipulation of biosynthetic enzymes, but chemical tools for probing GAG function are limited. HS and CS possess a conserved xylose residue that links the polysaccharide chain to a protein backbone. Here we report that, in zebrafish embryos, the peptide‐proximal xylose residue can be metabolically replaced with a chain‐terminating 4‐azido‐4‐deoxyxylose (4‐XylAz) residue by administration of UDP‐4‐azido‐4‐deoxyxylose (UDP‐4‐XylAz). UDP‐4‐XylAz disrupted both HS and CS biosynthesis and caused developmental abnormalities reminiscent of GAG biosynthesis and laminin mutants. The azide substituent of protein‐bound 4‐XylAz allowed for rapid visualization of the organismal sites of chain termination in vivo through bioorthogonal reaction with fluorescent cyclooctyne probes. UDP‐4‐XylAz therefore complements genetic tools for studies of GAG function in zebrafish embryogenesis.
Controlling Covalent Connection and Disconnection with Light
Authors: Göstl Robert , Hecht Stefan
Published: February 2014

The on‐going need for feature miniaturization and the growing complexity of structures for use in nanotechnology demand the precise and controlled formation of covalent bonds at the molecular level. Such control requires the use of external stimuli that offer outstanding spatial, temporal, as well as energetic resolution. Thus, photoaddressable switches are excellent candidates for creating a system that allows reversible photocontrol over covalent chemical connection and disconnection. Here we show that the formation of covalent bonds between two reagents and their scission in the resulting product can be controlled exclusively by illumination with differently colored light. A furyl‐substituted photoswitchable diarylethene was shown to undergo a reversible Diels–Alder reaction with maleimide to afford the corresponding Diels–Alder adduct. Our system is potentially applicable in any field already relying on the benefits of reversible Diels–Alder reactions.