bluuebunny/crossref_metadata_2025 huggingface dataset:
Mannitol for Paraphimosis Reduction
Authors: Anand Ajay , Kapoor Sahil
Published: January 2013

Introduction: Paraphimosis is a urologic emergency. Many treatment options have been devised for managing this entity. The osmotic method is one of them. We used an osmotic diuretic, mannitol, for reducing paraphimosis. Mannitol is commonly used for conditions like head injury to decrease cerebral oedema, partial nephrectomy and hepatorenal syndrome; we attempted using this diuretic for reducing paraphimosis. This is a novel technique and an application of mannitol which has never been reported before. Methods: Starting in February 2011, we used mannitol 20% in patients presenting to urologic emergency with uncomplicated paraphimosis. Mannitol-soaked gauzes were wrapped around the oedematous prepuce, followed by minimal intermittent hand compression and frequent resoaking of the gauze with 20% mannitol. No needle punctures were made. The soaked gauze was removed and the paraphimosis was reduced easily. Results: A complete reduction of paraphimosis occurred after mannitol-soaked gauze had been placed over the oedematous prepuce for about 30–45 min in 6 of our patients. This is a novel agent used for this entity; it reduces paraphimosis in a minimal time with no pain, with the added advantage of the least risk of infection after the procedure as opposed to granulated sugar or 50% dextrose previously used as osmotic agents. Conclusions: Mannitol can be applied in clinical practice for reducing paraphimosis. It requires no anaesthesia and is associated with minimal/no patient discomfort unlike that seen with multiple needle punctures and the various other non-osmotic methods of reducing paraphimosis.
Deep Vein Thrombosis and Pulmonary Embolism in a Child with Diabetic Ketoacidosis and Protein S Deficiency: A Case Report
Authors: Sdogou Triantafyllia , Kossiva Lydia , Kakleas Kostas , Platokouki Helen , Tentolouri Theodora , Georgouli Helen , Karayianni Christina , Karavanaki Kyriaki
Published: January 2013

Introduction: Diabetic ketoacidosis (DKA) is considered a hypercoagulable state, which may be exacerbated in patients with thrombophilia and lead to thrombosis. Case Report: We report on a 5.5-year-old boy, who was admitted to the pediatric department with DKA due to newly diagnosed type 1 diabetes. Low-grade fever was reported for 6 days prior to admission and continued during DKA management, with negative septic screening. After DKA management, the child developed symptoms of iliofemoral deep vein thrombosis (DVT). A family history of protein S (PS) deficiency was revealed. He was initially treated intravenously with antibiotics and unfractionated heparin, which, after 2 days, was switched to low-molecular-weight heparin and vitamin K antagonist (VKA) due to poor anticoagulant response. On the 6th day of anticoagulant treatment, the patient presented with pulmonary embolism (PE); he continued with VKA and antibiotics, with significant clinical improvement. Prolonged fever was attributed to DVT and PE. The patient was discharged on oral anticoagulants and insulin. Conclusion: We report on a child with congenital PS deficiency and DKA who developed DVT and PE despite anticoagulant treatment. It is important in children presenting with DKA to seek thoroughly for a medical history of thrombophilia and to start early thromboprophylaxis in such cases in order to prevent a possible thrombosis.
Height Deficit and Impairment of the GH/IGF-1 Axis in Patients Treated for Acute Lymphoblastic Leukemia during Childhood
Authors: Vilela Maria Ivone Oliveira Pinto , Serravite Marina de Oliveira , Oliveira Natália Bragança , de Brito Patrícia Carneiro , Ribeiro-Oliveira Jr. Antônio , Viana Marcos Borato
Published: January 2013

Background: Endocrine complications after acute lymphoblastic leukemia (ALL) are common. Methods: Final height, GH/IGF-1 axis, and body mass index were analyzed after 13.7 (7.0–20.7) years from diagnosis in 34 boys aged <12 years at diagnosis and 41 girls <10 years at diagnosis. A modified German BFM-83 ALL protocol included (n = 42) or did not include (n = 33) prophylactic cranial irradiation. In 27 patients, GH after insulin tolerance test, IGF-1, cortisol, free T4 and estradiol/testosterone were determined. Results: Final height was significantly reduced (mean Z-score for height between final height and diagnosis, ΔHAZ = –0.61, p = 0.0001). At that point, 3 patients were obese (4%) and 17 were overweight (22.7%). Patients aged ≤4 years at diagnosis and those irradiated had a greater loss in final height (p = 0.001 and p = 0.008, respectively). Abnormalities in GH/IGF-1 axis were observed in 4 patients: 3 had a GH peak <6 ng/ml and 1 had a serum IGF-1 concentration <25 ng/ml. Growth deficit was significantly higher in patients with hormonal deficiency (p = 0.006). Conclusions: Treatment of ALL during childhood is associated with final height deficit. Young age at diagnosis and radiotherapy were the major risk factors. GH/IGF-1 deficiency was found particularly in irradiated patients, even though it was detected in 1 non-irradiated patient.
Autophagy and Crohn's Disease
Authors: Nguyen Hang Thi Thu , Lapaquette Pierre , Bringer Marie-Agnès , Darfeuille-Michaud Arlette
Published: January 2013

Advances in genetics have shed light on the molecular basis of Crohn's disease (CD) predisposition and pathogenesis, via linkage disequilibrium analysis to genome-wide association studies. The discovery of genetic variants of NOD2, an intracellular pathogen molecular sensor, as risk factors for CD has paved the way for further research on innate immunity in this disease. Remarkably, polymorphisms in autophagy genes, such as ATG16L1 and IRGM, have been identified, allowing the pivotal role of autophagy in innate immunity to be uncovered. In this review, we summarize recent studies on the CD-associated NOD2, ATG16L1 and IRGM risk variants and their contribution to the autophagy functions that have most influenced our understanding of CD pathophysiology.
Learning in Diversities of Structures of Social Practice: Accounting for How, Why and Where People Learn Science
Authors: Bell Philip , Tzou Carrie , Bricker Leah , Baines AnnMarie D.
Published: January 2013

This paper outlines a theoretical framework intended to provide a more ecological and holistic accounting of how, why and where people learn in relation to constructs of human difference – race, class, disability designation, etc. – as learners circulate across places and associated operating value systems over multiple timescales. The framework for cultural learning pathways is an application and elaboration of Ole Dreier’s theory of persons in diversities of structures of social practice with a focus on the learning of disciplinary practices and the development of discipline-related identities. We summarize relevant learning phenomena along extended cultural pathways from three team ethnographies of science learning. We outline how power-related issues associated with privilege and marginalization are attended to in relation to the social, cultural, and material circumstances of learning within and across environments and discuss future research opportunities.
Daily Ultrafiltration Results in Improved Blood Pressure Control and More Efficient Removal of Small Molecules during Hemodialysis
Authors: Jones James P. , Leonard Edward F. , Sandhu Gagangeet , Winkel Gary , Levin Nathan W. , Cortell Stanley
Published: January 2013

Background: Although prior studies have shown that frequent hemodialysis (HD) can lead to improved control of dry weight in end-stage renal disease patients, there are no clinical studies examining whether this can improve blood pressure (BP) control and can also shorten the dialysis time needed to achieve satisfactory removal of small molecules. Several models of wearable dialysis systems are now under various stages of development. These devices present the possibility of hemodialyzing patients to their dry weights. We have built a prototype of a wearable ultrafiltration (UF) device that can provide daily UF. Apart from better fluid control, we hypothesize that separating HD from UF will result in better BP control, and adequate weekly small molecule removal could be achieved with a decreased duration of dialysis. We tested the hypothesis in current HD patients using conventional dialysis equipment. Methods: Thirteen patients were selected from a large urban HD center. The experimental period consisted of 4 weeks of daily UF (4 days/week of UF alone and 2 days/week of HD with UF). The duration of the HD sessions was increased by 15–30 min to maintain weekly standard Kt/V >2.0. The patients were then returned to their conventional 3 days/week of HD with UF and studied for 4 weeks. Predialysis BPs, interdialytic weight gains, and Kt/V results of the experimental and return periods were compared with those of the 3-month control period. No changes were made in antihypertensive or other medication during the study. Results: During the experimental period, mean arterial pressure decreased from 110 to 95 mm Hg (p < 0.001), systolic BP from 158 to 136 mm Hg (p < 0.001), while interdialytic weight gains were reduced from 3.25 to 1.21 liters (p < 0.0001). During the experimental period, weekly standard Kt/V of 2.16 was achieved in 8.24 h/week of HD, as compared to 11.14 h/week. Conclusions: Volume control with daily UF results in improved BP control and, by separating the UF function from HD, adequate weekly standard Kt/V >2 can be achieved with twice weekly HD.
A Case of Acute Prochloraz-Manganese Complex Intoxication Treated with Extracorporeal Elimination
Authors: Gil Hyowook , Seok Sujin , Hong Jungrak , Jeong Mihye , Hong Saeyong
Published: January 2013

Background/Aim: We treated a patient with critical manganese intoxication with vigorous extracorporeal elimination. In this article, we describe the clinical characteristics and treatment modalities of the patient. Patient: A 65-year-old man was brought to the emergency room (ER) 5.5 h after ingesting prochloraz-manganese complex. He experienced circulatory collapse and went into a coma without self-breathing on arrival at the ER. Mechanical ventilation was initiated and hemoperfusion, hemodialysis and continuous venovenous hemodiafiltration were performed with the help of norepinephrine. Measurement and Result: The manganese levels on the first, second and fourth hospital days were 34.1, 23.6 and 12.5 µg/l, respectively. He recuperated from the shock state within 7 hospital days. After 4 critical weeks, the patient regained full consciousness. Conclusion: Rigorous extracorporeal elimination by hemoperfusion, hemodialysis and continuous venovenous hemodiafiltration was an effective treatment modality for patients with acute manganese intoxication.
Phenotypes in Swiss Patients with Familial ALS Carrying TARDBP Mutations
Authors: Czell D. , Andersen P.M. , Morita M. , Neuwirth C. , Perren F. , Weber M.
Published: January 2013

Background: Recently, mutations in the TARDBP gene encoding the TAR DNA-binding protein 43 (TDP-43) have been identified in some familial amyotrophic lateral sclerosis (ALS) and sporadic ALS patients. The phenotype and frequency of TARDBP mutation carriers reportedly varies greatly among European populations. Objective: To define the phenotypic spectrum of TARDBP mutations and their frequency in a Swiss population. Methods: A total of 225 patients diagnosed with ALS (182 sporadic cases, 43 familial cases) were screened for TARDBP mutations. All patients were carefully examined and interviewed for a familial predisposition. Except for 1 patient who was followed at the University of Geneva, all patients were followed at the Kantonsspital St. Gallen. Results: 43 patients (19.5%) had a definite family history for ALS. A TARDBP mutation was identified in 4 of these (9.3%). Two female ALS patients carried the p.Asn352Ser mutation. Both had limb onset and a slowly progressive course of the disease. A novel mutation (p.Gly376Asp) was identified in a 44-year-old female patient. Survival amongst affected family members varied between 6 and 18 months. The patient and also the other siblings affected with ALS had an accessory nipple. A fourth male patient carried the p.Ala90Val mutation. None of the patients had overt cognitive impairment. TARDBP mutations were not found among patients with sporadic forms of ALS. Conclusion: In this Swiss population, the frequency of familial ALS is higher than reported earlier in other populations. The novel p.Gly376Asp TARDBP mutation is associated with rapid disease progression and may be associated with an accessory nipple while the p.Asn352Ser mutation is associated with slow disease progression.
Prescribing Pattern of Bryophyllum Preparations among a Network of Anthroposophic Physicians
Authors: Simões-Wüst Ana Paula , Jeschke Elke , Mennet Mónica , Schnelle Martin , Matthes Harald , von Mandach Ursula
Published: January 2013

Background: The use of preparations from Bryophyllum pinnatum for tocolysis (or to arrest labor) is supported by observations obtained mainly at empirical level, but also by preclinical experiments performed with uterus strips and myometrium cell lines. Furthermore, a retrospective matched-pair study revealed good tolerability and effectiveness. In anthroposophic medicine, however, Bryophyllum species are used for a broad spectrum of diagnoses. Here, we characterize the prescribing pattern of Bryophyllum preparations in a network of anthroposophic physicians in Germany. Methods: 38 primary-care physicians in Germany participated in the EvaMed network, a multi-center observational study. They documented anonymized prescriptions, diagnoses and demographic data (age and gender) for each consecutive patient between 01.01.2004 and 01.01.2010. Diagnoses were coded according to the 10th revision of the International Classification of Diseases (ICD-10). In the present analysis, all prescriptions of any Bryophyllum preparation in the resulting data bank were identified and the corresponding diagnoses were analyzed retrospectively. Results: A total of 4,038 prescriptions of Bryophyllum preparations were identified in the EvaMed data bank. A variety of preparations could be found, 77.7% of which were prepared from Bryophyllum plants exclusively and 22.5% were combinations. Bryophyllum preparations were often prescribed to treat ‘mental and behavioral disorders’ (ICD-10 F00–F99, 35.7%) and ‘diseases of the skin and subcutaneous tissue’ (L00–L99, 16.0%), followed by ‘symptoms, signs, and abnormal clinical and laboratory findings, not elsewhere classified diseases’ (R00–R99, 15.2%) and ‘diseases of the nervous system’ (G00– G99, 9.7%). Conclusion: By revealing the use of Bryophyllum preparations in so many other indications than preterm delivery, our data clearly show the urgent need to conduct additional clinical trials.
Aortic Distensibility and Extent and Complexity of Coronary Artery Disease in Patients with Stable Hypertensive and Nonhypertensive Coronary Artery Disease
Authors: Elbasan Zafer , Şahin DurmuşYıldıray , Gür Mustafa , Gözübüyük Gökhan , Akıllı Rabia Eker , Koyunsever Nermin Yıldız , Türkoğlu Caner , Kıvrak Ali , Yıldırım Arafat , Çaylı Murat
Published: January 2013

Objective: To assess the relationship between aortic distensibility (AD) and the extent and complexity of atherosclerotic lesions assessed with SYNTAX score (SS) in patients with stable coronary artery disease. Subjects and Methods: Three hundred and seventy-six consecutive patients (230 males and 146 females; mean age: 61.6 ± 9.9 years) with angiographically proven coronary artery disease were included in the study. The SS was calculated using the SS algorithm on the baseline diagnostic angiogram in the 376 patients. AD was calculated from the echocardiographically derived ascending aorta diameters and hemodynamic pressure measurements in all patients. Frequencies of risk factors, biochemical and hematological data were recorded. The patients were divided into two groups according to the median AD value as ADlow and ADhigh groups. Results: The SS was higher in the ADlow group compared with the ADhigh group (18.5 ± 10.2 vs. 8.3 ± 5.9, p < 0.001). The AD was independently related to age (β = -0.104, p = 0.019), hypertension (β = -0.202, p < 0.001) and SS (β = -0.457, p < 0.001) and was more strongly associated with SS in hypertensive patients compared to nonhypertensive patients (r = -0.524 vs. r = -0.414, p < 0.001 for all). Conclusion: The findings showed that impaired AD might be an independent predictor for the severity of coronary atherosclerosis, particularly in patients with hypertension.
New Variants of Lepidoptericidal Toxin Genes Encoding Bacillus thuringiensis Vip3Aa Proteins
Authors: Sauka Diego H. , Rodriguez Sonia E. , Benintende Graciela B.
Published: January 2013

Bacillus thuringiensis is an entomopathogenic bacterium characterized by producing parasporal proteinaceous insecticidal crystal inclusions during sporulation. Many strains are capable of also expressing other insecticidal proteins called Vip during the vegetative growing phase. Particularly, Vip3A proteins have activity against certain Lepidoptera species through a unique mechanism of action which emphasized their possible use in resistance management strategies against resistant pests. The aim of the work was to develop a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method that can distinguish between vip3A genes from B. thuringiensis strains. In addition, 4 novel vip3Aa genes were cloned and sequenced. The method was originally based on amplification of a single PCR amplicon and the use of 2 restriction enzymes with recognition sites that facilitate simultaneous detection. Subsequently, a third restriction enzyme was used to distinguish between vip3A variants. Thirteen vip3Aa genes were identified in strains belonging to 10 different B. thuringiensis serovars. Three intra-subclass variants of vip3Aa genes could be differentiated. The presented method can serve as an invaluable tool for the investigation of known and novel vip3A genes in B. thuringiensis strains. To the best of our knowledge, this is the first report where variants of a same subclass of insecticidal genes could be distinguished following PCR-RFLP.
The Impact of Shift Work on Brazilian Train Drivers with Different Chronotypes: A Comparative Analysis through Objective and Subjective Criteria
Authors: de Araújo Fernandes Jr. Silvio , Stetner Antonietti Leandro , Saba Amanda , Paulino de Faria Alexandre , Maculano Esteves Andrea , Tufik Sergio , Túlio de Mello Marco
Published: January 2013

Objective: The aim of this study was to compare sleep pattern, tiredness sensation and quality of life between different chronotypes in train drivers from a Brazilian transportation company. Subjects and Methods: Ninety-one train drivers, working a rotary work schedule including night shift, were divided into three groups according to their chronotype (morning types, intermediate or evening types) and were assessed for their sleep and quality of life, as characterized by a subjective questionnaire and the Psychomotor Vigilance Task (PVT), applied before and immediately after the night shift. The pattern of activity and rest was measured for 10 days by actigraphy, and the chronotype was determined through the Morningness-Eveningness Questionnaire. Results: Forty-one (45.1%) individuals were classified as morning type, 44 (48.4%) were classified as intermediate and 6 (6.6%) as evening type. The evening types had a tendency to remain awake for a longer period of time before the night shift (p = 0.05) and scored worse overall for quality of life compared to morning types (p = 0.11). There was no significant difference between the groups regarding variability in the PVT performance, even when covaried by the period of waking time before the test. There was no significant difference either in feelings of fatigue before and after starting the shift. Conclusion: Although the evening type number was small, evening type individuals scored worse relative to sleep and quality of life than morning type individuals.
Renal Antifibrotic Effect of N-Acetyl-Seryl-Aspartyl-Lysyl-Proline in Diabetic Rats
Authors: Castoldi G. , di Gioia C.R.T. , Bombardi C. , Preziuso C. , Leopizzi M. , Maestroni S. , Corradi B. , Zerbini G. , Stella A.
Published: January 2013

Background and Aim: Diabetic nephropathy is the main cause of end-stage renal disease. N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP), a physiological tetrapeptide hydrolyzed by the angiotensin-converting enzyme (ACE), has antifibrotic effects in the cardiovascular system and in the kidney in experimental models of hypertension, heart failure and renal disease. The aim of the study was to evaluate the effect of Ac-SDKP in diabetic nephropathy and the potential additive effect of Ac-SDKP, when compared to ACE inhibitors alone, on the development of renal fibrosis. Method: Diabetes was induced in 28 Sprague-Dawley rats by a single intraperitoneal injection of streptozotocin. Control rats (n = 10) received only buffer solution. An ACE inhibitor (ramipril, 3 mg/kg/day) was administered to 11 diabetic rats. After 2 months, Ac-SDKP (1 mg/kg/day) was administered by osmotic minipumps for 8 weeks to 7 diabetic rats and to 6 diabetic rats treated with ramipril. Osmotic minipumps delivered saline solution in the corresponding sham-treated rats (diabetic rats, n = 10, and ramipril-treated diabetic rats, n = 5). Results: Diabetic rats showed a significant increase in blood glucose level, urinary albumin excretion and renal fibrosis, and a reduction of glomerular nephrin expression with respect to control rats. Ac-SDKP administration significantly reduced renal fibrosis in diabetic rats, without significantly reducing urinary albumin excretion. Ramipril treatment caused a significant decrease in albuminuria and renal fibrosis and restored glomerular nephrin expression. Administration of Ac-SDKP, in addition to ramipril, further reduced renal fibrosis with respect to ramipril alone, while it did not improve the antiproteinuric effect of ramipril. Conclusion: Ac-SDKP administration reduces renal fibrosis in diabetic nephropathy. Addition of Ac-SDKP to ACE inhibition therapy improves the reduction of renal fibrosis with respect to ACE inhibition alone, suggesting a beneficial effect of this pharmacological association in diabetic nephropathy.
Surgical Technique and Recurrence in Cholesteatoma: A Meta-Analysis
Authors: Tomlin Julia , Chang David , McCutcheon Brandon , Harris Jeffrey
Published: January 2013

Conflicting reports and surgeon opinions have contributed to a long-standing debate regarding the merits of the intact canal wall versus canal wall down approach to cholesteatoma. The objective of this analysis was to identify and synthesize available data concerning rates of recidivism after the two primary types of cholesteatoma surgery. PubMed, Cochrane Collaboration, and Google Scholar searches were performed and articles filtered based on predetermined exclusion criteria. Individually reported rates of recurrent and residual disease were extracted and recorded. Meta-analysis demonstrated a relative risk of 2.87 with a confidence interval of 2.45–3.37, confirming a significantly increased incidence of postoperative cholesteatoma when using an intact canal wall approach rather than a canal wall down approach. Next, rates of recidivism following the typical two-stage intact canal wall operation were compared with a single-stage canal wall down operation and found to be similar. In conclusion, we advocate that greater consideration should be given to the canal wall down procedure in initial surgical management and identify the need for further exploration of rates of recidivism after staged or second-look procedures.
Observational Occurrence of Tropical Cyclone Ducts from GPS Dropsonde Data
Authors: Ding Juli , Fei Jianfang , Huang Xiaogang , Cheng Xiaoping , Hu Xiaohua
Published: January 2013

On the basis of global positioning system dropsonde data, Japan Meteorology Agency Regional Spectral Model analysis data, National Centers for Environmental Prediction reanalysis data, satellite products from the Naval Research Laboratory, and best-track tropical-cyclone (TC) datasets from the Shanghai Typhoon Institute, the statistical characteristics of the ducts induced by TCs (TC ducts) over the western North Pacific Ocean were analyzed for the period from September 2003 to September 2006, and two typical strong-duct cases with remarkable differences in formation cause were analyzed and compared. Of the total of 357 dropsondes, there are 212 cases that show ducting conditions, with an occurrence percentage of ~59%. Of the 212 TC-duct events, profiles with multiple ducting layers make up nearly one-half, with the main type of ducts being elevated ducts; in contrast, weak ducts make up over one-half, resulting in a weak median duct strength and thickness. Ducts formed in the transition zone, especially on the left side of TC tracks, tend to be much stronger and thicker than those formed inside TCs. The former are induced by the interaction between TCs and their surrounding systems, such as the inrush of dry and cold air from the north on the left side of TC tracks. The latter are associated with successive subsidence in the gaps between spiral cloud bands. With increasing TC intensities, the associated ducts inside TCs tend to be much stronger and thicker and to appear at higher altitudes.
A Large-Eddy Simulation Study of Thermal Effects on Turbulence Coherent Structures in and above a Building Array
Authors: Park Seung-Bu , Baik Jong-Jin
Published: January 2013

Thermal effects on turbulent flow in and above a cubical building array are numerically investigated using the parallelized large-eddy simulation model (PALM). Two cases (no heating and bottom heating) are simulated and are compared with each other, focusing on thermal effects on turbulence coherent structures. In the no-heating case, the streaky or streamwise-elongated structures of low-speed regions appear above the building array and ejections in the low-speed regions play an important role in transporting momentum downward. In the bottom-heating case, plume-shaped structures appear with streamwise-elongated structures and the magnitude of vertical turbulent momentum flux averaged over the low-speed regions increases. Elliptical structures of negative streamwise velocity perturbation and vortical structures similar to hairpin vortices appear above the building array in the conditionally averaged fields in both cases, and the coherent structures expand more vertically when the bottom is heated. At or just above the rooftop height, high-speed streaks are distinct and sweeps induced by the streaks or shear instability are important for momentum transport in both cases. In the bottom-heating case, the magnitude of vertical turbulent momentum flux at the tops of cavity spaces increases, partly owing to the strengthened ejections. Below the rooftop height, the high-speed streaks occasionally enter intersection spaces and induce spanwise diverging flow there in both cases. When the bottom is heated, intensified updrafts induce more organized secondary circular flow and the spanwise flow in the building array is strengthened by the secondary flow.
On the Mechanism Underlying the Spontaneous Emergence of Barotropic Zonal Jets
Authors: Bakas Nikolaos A. , Ioannou Petros J.
Published: January 2013

Zonal jets are commonly observed to spontaneously emerge in a β-plane channel from a background of turbulence that is sustained in a statistical steady state by homogeneous stochastic excitation and dissipation of vorticity. The mechanism for jet formation is examined in this work within the statistical wave–mean flow interaction framework of stochastic structural stability theory (SSST) that makes predictions for the emergence of zonal jets in β-plane turbulence. Using the coupled dynamical SSST system that governs the joint evolution of the second-order statistics and the mean flow, the structural stability of the spatially homogeneous statistical equilibrium with no mean zonal jets is studied. It is shown that close to the structural stability boundary, the eddy–mean flow dynamics can be split into two competing processes. The first, which is shearing of the eddies by the local shear described by Orr dynamics in a β plane, is shown in the limit of infinitesimal shear to lead to the formation of jets. The second, which is momentum flux divergence resulting from lateral wave propagation on the nonuniform local mean vorticity gradient, is shown to oppose jet formation. The upgradient momentum fluxes due to shearing of the eddies are shown to act exactly as negative viscosity for an anisotropic forcing and as negative hyperviscosity for isotropic forcing. The downgradient fluxes due to wave flux divergence are shown to act hyperdiffusively.
A Formulation of Three-Dimensional Residual Mean Flow Applicable Both to Inertia–Gravity Waves and to Rossby Waves
Authors: Kinoshita Takenari , Sato Kaoru
Published: January 2013

The three-dimensional (3D) residual mean flow is expressed as the sum of the Eulerian-mean flow and the Stokes drift. The present study derives formulas that are approximately equal to the 3D Stokes drift for the primitive equation (PRSD) and for the quasigeostrophic equation (QGSD) using small-amplitude theory for a slowly varying time-mean flow. The PRSD has a broad utility that is applicable to both Rossby waves and inertia–gravity waves. The 3D wave activity flux whose divergence corresponds to the wave forcing is also derived using PRSD. The PRSD agrees with QGSD under the small-Rossby-number assumption, and it agrees with the 3D Stokes drift derived by S. Miyahara and by T. Kinoshita et al. for inertia–gravity waves under the constant-Coriolis-parameter assumption. Moreover, a phase-independent 3D Stokes drift is derived under the QG approximation.

The 3D residual mean flow in the upper troposphere in April is investigated by applying the new formulas to the European Centre for Medium-Range Weather Forecasts (ECMWF) Interim Re-Analysis (ERA-Interim) data. It is observed that the PRSD is strongly poleward (weakly equatorward) upstream (downstream) of the storm track. A case study was also made for dominant gravity waves around the southern Andes in the simulation by a gravity wave–resolving general circulation model. The 3D residual mean flow associated with the gravity waves is poleward (equatorward) in the western (eastern) region of the southern Andes. This flow is due to the horizontal structure of the variance in the zonal component of the mountain waves, which do not change much while they propagate upward.
A Simple GCM Study on the Relationship between ENSO and the Southern Annular Mode
Authors: Gong Tingting , Feldstein Steven B. , Luo Dehai
Published: January 2013

This study investigates the relationship between El Niño–Southern Oscillation (ENSO) and southern annular mode (SAM) events with an idealized general circulation model. A series of model calculations are performed to examine why positive (negative) intraseasonal SAM events are observed to occur much more frequently during La Niña (El Niño). Seven different model runs are performed: a control run, three El Niño runs (the first with a zonally symmetric heating field, the second with a zonally asymmetric heating/cooling field, and the third that combines both fields), and three La Niña runs (with heating fields of opposite sign).

The model runs with the zonally symmetric and combined heating fields are found to yield the same relationship between the phase of ENSO and the preferred phase for SAM events as is observed in the atmosphere. In contrast, the zonally asymmetric model runs are found to have the opposite SAM–ENSO phase preference characteristics. Since a reduced midlatitude meridional potential vorticity gradient has been linked to a greater frequency of positive-phase SAM events, and vice versa for negative SAM events, the meridional potential vorticity gradient in the various model runs was compared. The results suggest that the phase preference of SAM events during ENSO arises from the impact of the zonal-mean heating on the midlatitude meridional potential vorticity gradient.
Turbulence and Vertical Fluxes in the Stable Atmospheric Boundary Layer. Part II: A Novel Mixing-Length Model
Authors: Huang Jing , Bou-Zeid Elie , Golaz Jean-Christophe
Published: January 2013

This is the second part of a study about turbulence and vertical fluxes in the stable atmospheric boundary layer. Based on a suite of large-eddy simulations in Part I where the effects of stability on the turbulent structures and kinetic energy are investigated, first-order parameterization schemes are assessed and tested in the Geophysical Fluid Dynamics Laboratory (GFDL)’s single-column model. The applicability of the gradient-flux hypothesis is first examined and it is found that stable conditions are favorable for that hypothesis. However, the concept of introducing a stability correction function fm as a multiplicative factor into the mixing length used under neutral conditions lN is shown to be problematic because fm computed a priori from large-eddy simulations tends not to be a universal function of stability. With this observation, a novel mixing-length model is proposed, which conforms to large-eddy simulation results much better under stable conditions and converges to the classic model under neutral conditions. Test cases imposing steady as well as unsteady forcings are developed to evaluate the performance of the new model. It is found that the new model exhibits robust performance as the stability strength is changed, while other models are sensitive to changes in stability. For cases with unsteady forcings, which are very rarely simulated or tested, the results of the single-column model and large-eddy simulations are also closer when the new model is used, compared to the other models. However, unsteady cases are much more challenging for the turbulence closure formulations than cases with steady surface forcing.
Squall-Line Intensification via Hydrometeor Recirculation
Authors: Seigel Robert B. , van den Heever Susan C.
Published: January 2013

Many studies have demonstrated the intimate connection between microphysics and deep moist convection, especially for squall lines via cold pool pathways. The present study examines four numerically simulated idealized squall lines using the Regional Atmospheric Modeling System (RAMS) and includes a control simulation that uses full two-moment microphysics and three sensitivity experiments that vary the mean diameter of the hail hydrometeor size distribution. Results suggest that a circulation centered at the freezing level supports midlevel convective updraft invigoration through increased latent heating. The circulation begins with hail hydrometeors that initiate within the convective updraft above the freezing level and are then ejected upshear because of the front-to-rear flow of the squall line. As the hail falls below the freezing level, the rear-inflow jet (RIJ) advects the hail hydrometeors downshear and into the upshear flank of the midlevel convective updraft. Because the advection occurs below the freezing level, some of the hail melts and sheds raindrops. The addition of hail and rain to the updraft increases latent heating owing to both an enhancement in riming and vapor deposition onto hail and rain. The increase in latent heating enhances buoyancy within the updraft, which leads to an increase in precipitation and cold pool intensity that promote a positive feedback on squall-line strength. The upshear-tilted simulated squall lines in this study indicate that as hail size is decreased, squall lines are invigorated through the recirculation mechanism.
Summer Land–Atmosphere Coupling Strength over the United States: Results from the Regional Climate Model RegCM4–CLM3.5
Authors: Mei Rui , Wang Guiling , Gu Huanghe
Published: January 2013

This study investigates the land–atmosphere coupling strength during summer over the United States using the Regional Climate Model version 4 (RegCM4)–Community Land Model version 3.5 (CLM3.5). First, a 10-yr simulation driven with reanalysis lateral boundary conditions (LBCs) is conducted to evaluate the model performance. The model is then used to quantify the land–atmosphere coupling strength, predictability, and added forecast skill (for precipitation and 2-m air temperature) attributed to realistic land surface initialization following the Global Land–Atmosphere Coupling Experiment (GLACE) approaches. Similar to previous GLACE results using global climate models (GCMs), GLACE-type experiments with RegCM4 identify the central United States as a region of strong land–atmosphere coupling, with soil moisture–temperature coupling being stronger than soil moisture–precipitation coupling, and confirm that realistic soil moisture initialization is more promising in improving temperature forecasts than precipitation forecasts. At a 1–15-day lead, the added forecast skill reflects predictability (or land–atmosphere coupling strength) indicating that that model can capture the realistic land–atmosphere coupling at a short time scale. However, at a 16–30-day lead, predictability cannot translate to added forecast skill, implying that the coupling at the longer time scale may not be represented well in the model. In addition, comparison of results from GLACE2-type experiments with RegCM4 driven by reanalysis LBCs and those driven by GCM LBCs suggest that the intrinsic land–atmosphere coupling strength within the regional model is the dominant factor for the added forecast skill at a 1–15-day lead, while the impact of LBCs from the GCM may play a dominant role in determining the signal of added forecast skill in the regional model at a 16–30-day lead. It demonstrates the complexities of using regional climate model for GLACE-type studies.
The Atmospheric Imaging Radar: Simultaneous Volumetric Observations Using a Phased Array Weather Radar
Authors: Isom Bradley , Palmer Robert , Kelley Redmond , Meier John , Bodine David , Yeary Mark , Cheong Boon-Leng , Zhang Yan , Yu Tian-You , Biggerstaff Michael I.
Published: January 2013

Mobile weather radars often utilize rapid-scan strategies when collecting observations of severe weather. Various techniques have been used to improve volume update times, including the use of agile and multibeam radars. Imaging radars, similar in some respects to phased arrays, steer the radar beam in software, thus requiring no physical motion. In contrast to phased arrays, imaging radars gather data for an entire volume simultaneously within the field of view (FOV) of the radar, which is defined by a broad transmit beam. As a result, imaging radars provide update rates significantly exceeding those of existing mobile radars, including phased arrays. The Advanced Radar Research Center (ARRC) at the University of Oklahoma (OU) is engaged in the design, construction, and testing of a mobile imaging weather radar system called the atmospheric imaging radar (AIR). Initial tests performed with the AIR demonstrate the benefits and versatility of utilizing beamforming techniques to achieve high spatial and temporal resolution. Specifically, point target analysis was performed using several digital beamforming techniques. Adaptive algorithms allow for improved resolution and clutter rejection when compared to traditional techniques. Additional experiments were conducted during two severe weather events in Oklahoma. Several digital beamforming methods were tested and analyzed, producing unique, simultaneous multibeam measurements using the AIR.
A Control-Volume Model of the Compressible Euler Equations with a Vertical Lagrangian Coordinate
Authors: Chen Xi , Andronova Natalia , Van Leer Bram , Penner Joyce E. , Boyd John P. , Jablonowski Christiane , Lin Shian-Jiann
Published: January 2013

Accurate and stable numerical discretization of the equations for the nonhydrostatic atmosphere is required, for example, to resolve interactions between clouds and aerosols in the atmosphere. Here the authors present a modification of the hydrostatic control-volume approach for solving the nonhydrostatic Euler equations with a Lagrangian vertical coordinate. A scheme with low numerical diffusion is achieved by introducing a low Mach number approximate Riemann solver (LMARS) for atmospheric flows. LMARS is a flexible way to ensure stability for finite-volume numerical schemes in both Eulerian and vertical Lagrangian configurations. This new approach is validated on test cases using a 2D (x–z) configuration.
Defining, Understanding, and Supporting Open Collaboration
Authors: Forte Andrea , Lampe Cliff
Published: January 2013

In this short introductory piece, we define open collaboration and contextualize the diverse articles in this special issue in a common vocabulary and history. We provide a definition of open collaboration and situate the phenomenon within an interrelated set of scholarly and ideological movements. We then examine the properties of open collaboration systems that have given rise to research and review major areas of scholarship. We close with a summary of consistent findings in open collaboration research to date.
The Influence of Cognitive Load on Transfer With Error Prevention Training Methods
Authors: Hutchins Shaun D. , Wickens Christopher D. , Carolan Thomas F. , Cumming John M.
Published: January 2013

Objective:

The objective was to conduct research synthesis for the U.S. Army on the effectiveness of two error prevention training strategies (training wheels and scaffolding) on the transfer of training.

Background:

Motivated as part of an ongoing program of research on training effectiveness, the current work presents some of the program’s research into the effects on transfer of error prevention strategies during training from a cognitive load perspective. Based on cognitive load theory, two training strategies were hypothesized to reduce intrinsic load by supporting learners early in acquisition during schema development.

Method:

A transfer ratio and Hedges’ g were used in the two meta-analyses conducted on transfer studies employing the two training strategies. Moderators relevant to cognitive load theory and specific to the implemented strategies were examined. The transfer ratio was the ratio of treatment transfer performance to control transfer. Hedges’ g was used in comparing treatment and control group standardized mean differences. Both effect sizes were analyzed with versions of sample weighted fixed effect models.

Results:

Analysis of the training wheels strategy suggests a transfer benefit. The observed benefit was strongest when the training wheels were a worked example coupled with a principle-based prompt. Analysis of the scaffolding data also suggests a transfer benefit for the strategy.

Conclusion:

Both training wheels and scaffolding demonstrated positive transfer as training strategies. As error prevention techniques, both support the intrinsic load–reducing implications of cognitive load theory.

Application:

The findings are applicable to the development of instructional design guidelines in professional skill-based organizations such as the military.
“I’m only grateful that it’s not a Cape Town book”, or: Zoë Wicomb, textuality, propriety, and the proprietary
Authors: van der Vlies Andrew
Published: January 2013

This essay considers the representation of authorship and of writing and reading in — and the manner in which various institutions of publication and reception negotiate the conditions of authorship of — South African-born, Scottish-resident author Zoë Wicomb’s first book, You Can’t Get Lost in Cape Town (1987). Variously described as a short-story cycle or novel-in-stories, this deftly metafictional work offers a meditation on the gender and race-inflected difficulties of authorship under apartheid, a condition in which language, race, and propriety, the issue of the properties of the literary and the ownership of stories, are inevitably imbricated. It asks how we might better understand the conditions of Wicomb’s work in its different editions and published versions by exploring the author’s engagement with ideas of authorship and responsibility. It asks what Wicomb’s representations of the propriety and the proprietary interests involved in postcolonial authorship reveal about her own work’s fate in the world, and what questions such an analysis poses for the study of postcolonial print — and literary — cultures.
Evc Regulates a Symmetrical Response to Shh Signaling in Molar Development
Authors: Nakatomi M. , Hovorakova M. , Gritli-Linde A. , Blair H.J. , MacArthur K. , Peterka M. , Lesot H. , Peterkova R. , Ruiz-Perez V.L. , Goodship J.A. , Peters H.
Published: January 2013

Tooth morphogenesis involves patterning through the activity of epithelial signaling centers that, among other molecules, secrete Sonic hedgehog (Shh). While it is known that Shh responding cells need intact primary cilia for signal transduction, the roles of individual cilia components for tooth morphogenesis are poorly understood. The clinical features of individuals with Ellis-van Creveld syndrome include various dental anomalies, and we show here that absence of the cilial protein Evc in mice causes various hypo- and hyperplasia defects during molar development. During first molar development, the response to Shh signaling is progressively lost in Evc-deficient embryos and, unexpectedly, the response consistently disappears in a buccal to lingual direction. The important role of Evc for establishing the buccal-lingual axis of the developing first molar is also supported by a displaced activity of the Wnt pathway in Evc mutants. The observed growth abnormalities eventually manifest in first molar microdontia, disruption of molar segmentation and symmetry, root fusions, and delayed differentiation. Analysis of our data indicates that both spatially and temporally disrupted activities of the Shh pathway are the primary cause for the variable dental anomalies seen in patients with Ellis-van Creveld syndrome or Weyers acrodental dysostosis.
The Geography of Drug Abuse Epidemiology Among Probationers in Baltimore
Authors: Wooditch Alese , Lawton Brian , Taxman Faye S.
Published: January 2013

Substance use is a pervasive health problem that contributes significantly to the recycling of offenders through the justice system. This study uses routine activities theory as a framework to determine whether the availability of illicit drugs in a probationer’s immediate residential environment is associated with their use of illegal substances. Combining narcotics-related calls for police service data, interviews with offenders, life history event calendars, and biological drug test results, a clustered-logit regression model of 250 drug-involved probationers indicates that the availability of drugs within the probationer’s immediate area is associated with a higher probability of testing positive for illicit substances. The results suggest a broader epidemiological framework to understand how environment affects drug use. Further research in this area will improve supervision practices of drug-involved individuals and interventions to reduce drug use.
Acoustical model for Shoddy-based fiber sound absorbers
Authors: Manning John , Panneton Raymond
Published: January 2013

A simple equivalent fluid model is proposed to describe the acoustic behavior of post-consumer and post-industrial recycled fibers otherwise known as Shoddies. The model requires knowledge of the bulk density only, a parameter that is easily measured. Characterization testing was completed on nine Shoddy fiber constructions processed by one of three different methods: thermal bonding, resin bonding, and mechanical bonding. The parameters measured directly were bulk density, open porosity, tortuosity, static airflow resistivity, and normal incidence sound absorption. The materials’ viscous and thermal characteristic lengths and static thermal permeability are determined using indirect acoustical techniques. Empirical relationships linking the material parameters to the bulk density are then substituted into several popular equivalent fluid models. The most accurate ‘simplified’ model is selected by comparing each model’s ability to accurately predict the materials’ acoustic behavior using normal incidence sound absorption to assess performance. The present work is of interest to sound engineers in predicting the acoustic performance of Shoddy-based absorbers.