bluuebunny/crossref_metadata_2025_split huggingface dataset:
Does the Holton–Tan Mechanism Explain How the Quasi-Biennial Oscillation Modulates the Arctic Polar Vortex?
Authors: Garfinkel Chaim I. , Shaw Tiffany A. , Hartmann Dennis L. , Waugh Darryn W. 
Published: February 2012

Abstract
Idealized experiments with the Whole Atmosphere Community Climate Model (WACCM) are used to explore the mechanism(s) whereby the stratospheric quasi-biennial oscillation (QBO) modulates the Northern Hemisphere wintertime stratospheric polar vortex. Overall, the effect of the critical line emphasized in the Holton–Tan mechanism is less important than the effect of the mean meridional circulation associated with QBO winds for the polar response to the QBO. More specifically, the introduction of easterly winds at the equator near 50 hPa 1) causes enhanced synoptic-scale Eliassen–Palm flux (EPF) convergence in the subtropics from 150 to 50 hPa, which leads to the subtropical critical line moving poleward in the lower stratosphere, and 2) creates a barrier to planetary wave propagation from subpolar latitudes to midlatitudes in the middle and upper stratosphere (e.g., less equatorward EPF near 50°N), which leads to enhanced planetary wave convergence in the polar vortex region. These two effects are mechanistically distinct; while the former is related to the subtropical critical line, the latter is due to the mean meridional circulation of the QBO. All of these effects are consistent with linear theory, although the evolution of the entire wind distribution is only quasi-linear because induced zonal wind changes cause the wave driving to shift and thereby positively feed back on the zonal wind changes. Finally, downward propagation of the QBO in the equatorial stratosphere, upper stratospheric equatorial zonal wind, and changes in the tropospheric circulation appear to be less important than lower stratospheric easterlies for the polar stratospheric response. Overall, an easterly QBO wind anomaly in the lower stratosphere leads to a weakened stratospheric polar vortex, in agreement with previous studies, although not because of changes in the subtropical critical line.
Pairing Measurements of the Water Vapor Isotope Ratio with Humidity to Deduce Atmospheric Moistening and Dehydration in the Tropical Midtroposphere
Authors: Noone David 
Published: February 2012

Abstract
Measurements of the isotope ratio of water vapor (expressed as the δ value) allow processes that control the humidity in the tropics to be identified. Isotopic information is useful because the change in δ relative to the water vapor mixing ratio (q) is different for different processes. The theoretical framework for interpreting paired q–δ data is established and based on a set of simple models that account for mixing and a range of condensation conditions. A general condensation model is derived that accounts for cloud precipitation efficiency and postcondensation exchange. Using data from the Tropospheric Emission Spectrometer (TES), aspects of subtropical hydrology are characterized by the match between theoretical curves and observed displacement in q–δ space. The subtropics are best described as the balance between drying associated with (mostly horizontal) transport of dry air from high latitudes and moistening by clouds with low precipitation efficiency. In the western Pacific moistening involves the import of air into which raindrops have evaporated and is identified by “super-Rayleigh” isotopic distillation. In the dry subtropics, the observations are consistent with the condensation–advection explanation for the humidity minimum but also reflect details of the cloud processes and moistening by high humidity filaments of tropical origin. In spite of limitations of the TES data, the success of the analysis highlights the value of using isotopic data in analysis of tropospheric moisture budgets and the role water isotopic ratio measurements can play in identifying mechanisms associated with large-scale changes in atmospheric humidity.
Computational Modes and Grid Imprinting on Five Quasi-Uniform Spherical C Grids
Authors: Weller Hilary , Thuburn John , Cotter Colin J. 
Published: February 2012

Abstract
Currently, most operational forecasting models use latitude–longitude grids, whose convergence of meridians toward the poles limits parallel scaling. Quasi-uniform grids might avoid this limitation. Thuburn et al. and Ringler et al. have developed a method for arbitrarily structured, orthogonal C grids called TRiSK, which has many of the desirable properties of the C grid on latitude–longitude grids but which works on a variety of quasi-uniform grids. Here, five quasi-uniform, orthogonal grids of the sphere are investigated using TRiSK to solve the shallow-water equations.
Some of the advantages and disadvantages of the hexagonal and triangular icosahedra, a “Voronoi-ized” cubed sphere, a Voronoi-ized skipped latitude–longitude grid, and a grid of kites in comparison to a full latitude–longitude grid are demonstrated. It is shown that the hexagonal icosahedron gives the most accurate results (for least computational cost). All of the grids suffer from spurious computational modes; this is especially true of the kite grid, despite it having exactly twice as many velocity degrees of freedom as height degrees of freedom. However, the computational modes are easiest to control on the hexagonal icosahedron since they consist of vorticity oscillations on the dual grid that can be controlled using a diffusive advection scheme for potential vorticity.
Automatic machine embroidery image color analysis system. Part I: Using Gustafson-Kessel clustering algorithm in embroidery fabric color separation
Authors: Kuo Chung-Feng Jeffrey , Jian Bo-Lin , Wu Han-Cheng , Peng Kai-Ching 
Published: February 2012

This series of studies aims to propose the automatic machine embroidery image color analysis system to solve the problem of lack of manpower for machine embroidery fabric drafting and to shorten drafting time. The studies included three parts: (1) machine embroidery image color separation, (2) search of repeated pattern images, (3) machine embroidery color analysis system integration. This study aimed to find the optimal clustering algorithm and cluster validity indices for the automatic color separation process of machine embroidery fabric drafting in order to shorten drafting time. To improve image quality for computer analysis, this study used the color hybrid median filter to filter noise and the color bilateral filter to smoothen fabric and embroidery texture for subsequent color separation. By extracting the color a* component and b* component of the machine embroidery image in CIE L*a*b* color system, this study used the Gustafson-Kessel clustering algorithm for color separation. The Gustafson-Kessel clustering algorithm in machine embroidery image color separation can improve color separation accuracy, and its result is compared with that of the clustering algorithms commonly used in the color separation of color images. This study implemented the chromatography of the color separation results, and used the cluster validity indices to prove that the application of Gustafson-Kessel clustering algorithm in the machine embroidery image color separation system has better results than K-means, K-medoid, fuzzy C-means (FCM), and self-organizing map (SOM) clustering algorithm. The results meet the classifications as expected by human eyes.
Accuracy Analysis of a Novel Electromagnetic Navigation Procedure Versus a Standard Fluoroscopic Method for Retrograde Drilling of Osteochondritis Dissecans Lesions of the Knee
Authors: Hoffmann Michael , Petersen Jan Philipp , Schröder Malte , Hartel Maximillian , Kammal Michael , Rueger Johannes Maria , Ruecker Andreas Hermann 
Published: February 2012

Background: Retrograde drilling for osteochondritis dissecans (OCD) remains a challenging operation. Purpose: A novel radiation-free electromagnetic navigation system (ENS)–based method was developed and its feasibility and accuracy for retrograde drilling procedures evaluated and compared with the standard freehand fluoroscopic method in an experimental setting. Study Design: Controlled laboratory study. Methods: A controlled laboratory study with 16 standard freehand fluoroscopically and 16 electromagnetically guided retrograde drilling procedures was performed on 8 cadaveric human knees. Four artificial cartilage lesions (2 on each condyle) were set per knee. Drilling accuracy was determined by final distance from the tip of the drill bit to the tip of the probe hook (D1) and distance between the tip of the drill and the marked lesion on the cartilage surface (D2). Intraoperative fluoroscopy exposure times were documented, as were directional readjustments or complete restarts. All procedures were timed using a stopwatch. Results: Successful retrograde drilling was accomplished in all 16 cases using the novel ENS-based method and in 11 cases using the standard fluoroscopic technique. The overall mean time for the fluoroscopy-guided procedures was 10 minutes 55 seconds ± 3 minutes 19 seconds and for the ENS method was 5 minutes 34 seconds ± 38 seconds, providing a mean time benefit of 5 minutes 35 seconds ( P < .001). Mean D1 was 3.8 ± 1.6 mm for the standard and 2.3 ± 0.6 mm using the ENS technique ( P = .021), and mean D2 was 2.5 ± 1.3 mm for the standard and 0.9 ± 0.7 mm for the ENS-based method ( P < .001). Conclusion: Compared with the standard fluoroscopic technique, the novel ENS-based method used in this study showed superior accuracy, required less time, and utilized no radiation. Clinical Relevance: The novel method improves a standard operating procedure in terms of accuracy, operation time for the retrograde drilling procedure, and radiation exposure.
B cell–intrinsic deficiency of the Wiskott-Aldrich syndrome protein (WASp) causes severe abnormalities of the peripheral B-cell compartment in mice
Authors: Recher Mike , Burns Siobhan O. , de la Fuente Miguel A. , Volpi Stefano , Dahlberg Carin , Walter Jolan E. , Moffitt Kristin , Mathew Divij , Honke Nadine , Lang Philipp A. , Patrizi Laura , Falet Hervé , Keszei Marton , Mizui Masayuki , Csizmadia Eva , Candotti Fabio , Nadeau Kari , Bouma Gerben , Delmonte Ottavia M. , Frugoni Francesco , Fomin Angela B. Ferraz , Buchbinder David , Lundequist Emma Maria , Massaad Michel J. , Tsokos George C. , Hartwig John , Manis John , Terhorst Cox , Geha Raif S. , Snapper Scott , Lang Karl S. , Malley Richard , Westerberg Lisa , Thrasher Adrian J. , Notarangelo Luigi D. 
Published: February 2012

AbstractWiskott Aldrich syndrome (WAS) is caused by mutations in the WAS gene that encodes for a protein (WASp) involved in cytoskeleton organization in hematopoietic cells. Several distinctive abnormalities of T, B, and natural killer lymphocytes; dendritic cells; and phagocytes have been found in WASp-deficient patients and mice; however, the in vivo consequence of WASp deficiency within individual blood cell lineages has not been definitively evaluated. By conditional gene deletion we have generated mice with selective deficiency of WASp in the B-cell lineage (B/WcKO mice). We show that this is sufficient to cause a severe reduction of marginal zone B cells and inability to respond to type II T-independent Ags, thereby recapitulating phenotypic features of complete WASp deficiency. In addition, B/WcKO mice showed prominent signs of B-cell dysregulation, as indicated by an increase in serum IgM levels, expansion of germinal center B cells and plasma cells, and elevated autoantibody production. These findings are accompanied by hyperproliferation of WASp-deficient follicular and germinal center B cells in heterozygous B/WcKO mice in vivo and excessive differentiation of WASp-deficient B cells into class-switched plasmablasts in vitro, suggesting that WASp-dependent B cell–intrinsic mechanisms critically contribute to WAS-associated autoimmunity.
How I treat with anticoagulants in 2012: new and old anticoagulants, and when and how to switch
Authors: Schulman Sam , Crowther Mark A. 
Published: February 2012

Abstract
Two novel oral anticoagulants, dabigatran and rivaroxaban, have recently been approved. They differ in many ways from warfarin, including rapid onset of action, shorter half-life, fewer drug-drug interactions, lack of need for monitoring, and no need for titration or dose adjustments. These novel agents represent a landmark shift in anticoagulant care; however, many aspects of their use will be unfamiliar to practicing clinicians, despite the imminent widespread use of these agents in the community. The management of these anticoagulants when transitioning from or back to warfarin, around surgery or in case of major hemorrhage, requires knowledge of their pharmacokinetics and mechanism of action. Unfortunately, there is a limited evidence base to inform decisions around management of these agents. We present our practice in these settings supported, where available, with literature evidence.
Function and biotechnology of extremophilic enzymes in low water activity
Authors: Karan Ram , Capes Melinda D , DasSarma Shiladitya 
Published: February 2012

Abstract
Enzymes from extremophilic microorganisms usually catalyze chemical reactions in non-standard conditions. Such conditions promote aggregation, precipitation, and denaturation, reducing the activity of most non-extremophilic enzymes, frequently due to the absence of sufficient hydration. Some extremophilic enzymes maintain a tight hydration shell and remain active in solution even when liquid water is limiting, e.g. in the presence of high ionic concentrations, or at cold temperature when water is close to the freezing point. Extremophilic enzymes are able to compete for hydration via alterations especially to their surface through greater surface charges and increased molecular motion. These properties have enabled some extremophilic enzymes to function in the presence of non-aqueous organic solvents, with potential for design of useful catalysts. In this review, we summarize the current state of knowledge of extremophilic enzymes functioning in high salinity and cold temperatures, focusing on their strategy for function at low water activity. We discuss how the understanding of extremophilic enzyme function is leading to the design of a new generation of enzyme catalysts and their applications to biotechnology.
Study of Ultrathin Films of P3HT/PCBM by Means of Highly Sensitive Absorption Spectroscopy
Authors: Yaguchi Kaori , Furube Akihiro , Katoh Ryuzi 
Published: February 2012

Abstract
Ultrathin films of P3HT and P3HT/PCBM prepared on glass and ITO glass substrates by spin-coating were studied by means of highly sensitive absorption spectroscopy. For pristine P3HT films, we discuss the morphology and electronic structure at the interface between the substrate and the P3HT layer. For P3HT/PCBM films, we found that phase separation could be controlled by changing the concentration of the solutions used to prepare the films.
Relationships between muscle size and hardness of the medial gastrocnemius at different ankle joint angles in young men
Authors: Akagi Ryota , Chino Kentaro , Dohi Michiko , Takahashi Hideyuki 
Published: February 2012

Background Measurement of muscle hardness is important for objective evaluation of the muscle condition. Muscle hardness may be related to muscle size, but this relationship has not yet been examined. Purpose To examine the relationship between the size and hardness of the medial gastrocnemius muscle (MG) at different ankle joint angles. Material and Methods Twelve young male subjects comprised the present study. Muscle thickness of the right MG (MTMG) was measured by ultrasonography as an index of muscle size. The MTMG was determined at 30% of the lower leg length from the popliteal crease to the lateral malleolus. At the same site, muscle hardness of the right MG (MHMG) was measured with ultrasound real-time tissue elastography. Both measurements were taken while each subject was instructed to lie in a prone position on a test bench. The right ankle was secured to a handmade apparatus by a non-elastic belt, with the hip and knee joints fully extended and the ankle positioned at +30°, 0° and –20° (0°: neutral position, positive values indicating plantar flexion). Results There were no significant differences in the MTMG among the ankle joint angles whereas the MHMG significantly increased as the ankle was moved from plantar flexion to dorsiflexion. As a result, there was a difference in the MTMG-MHMG relationship between the angles. The MTMG significantly correlated with the MHMG only at +30° (r = 0.635, P < 0.05) where passive torque around the ankle has been shown to be near zero in previous studies. Conclusion The hardness of the relaxed MG with no passive tension appears to depend on its size.
Thin-section CT findings of patients with acute Streptococcus pneumoniae pneumonia with and without concurrent infection
Authors: Okada F , Ando Y , Matsushita S , Ishii R , Nakayama T , Morikawa K , Ono A , Maeda T , Mori H 
Published: February 2012

Objectives: The aim of this study was to compare the pulmonary thin-section CT findings of patients with acute Streptococcus pneumoniae pneumonia with and without concurrent infection.
Methods: The study group comprised 86 patients with acute S. pneumoniae pneumonia, 36 patients with S. pneumoniae pneumonia combined with Haemophilus influenzae infection, 26 patients with S. pneumoniae pneumonia combined with Pseudomonas aeruginosa infection and 22 patients with S. pneumoniae pneumonia combined with methicillin-susceptible Staphylococcus aureus (MSSA) infection. We compared the thin-section CT findings among the groups.
Results: Centrilobular nodules and bronchial wall thickening were significantly more frequent in patients with pneumonia caused by concurrent infection (H. influenzae: p&lt;0.001 and p&lt;0.001, P. aeruginosa: p&lt;0.001 and p&lt;0.001, MSSA: p&lt;0.001 and p&lt;0.001, respectively) than in those infected with S. pneumoniae alone. Cavity and bilateral pleural effusions were significantly more frequent in cases of S. pneumoniae pneumonia with concurrent P. aeruginosa infection than in cases of S. pneumoniae pneumonia alone (p&lt;0.001 and p&lt;0.001, respectively) or with concurrent H. influenzae (p&lt;0.05 and p&lt;0.001, respectively) or MSSA infection (p&lt;0.05 and p&lt;0.05, respectively).
Conclusions: When a patient with S. pneumoniae pneumonia has centrilobular nodules, bronchial wall thickening, cavity or bilateral pleural effusions on CT images, concurrent infection should be considered.
Intensity-modulated radiotherapy for nasopharyngeal carcinoma: improvement of the therapeutic ratio with helical tomotherapy vs segmental multileaf collimator-based techniques
Authors: Chen A M , Yang C C , Marsano J , Liu T , Purdy J A 
Published: February 2012

Objectives: The aim of the study was to compare differences in dosimetric, clinical and quality-of-life end points among patients treated with helical tomotherapy (HT) and segmental multileaf collimator (SMLC)-based intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma.
Methods: From June 2005 to August 2009, 30 consecutive patients were treated with IMRT for nasopharyngeal carcinoma to a dose of 70 Gy. 14 patients (47%) were treated using HT and 16 (53%) were treated using SMLC-based IMRT. 28 patients (93%) received concurrent chemotherapy. The patients were evenly balanced between the two radiotherapy groups with respect to clinical and pathological characteristics. Median follow-up was 30 months (range, 6–62 months).
Results: The 2-year estimates of overall survival, local–regional control and progression-free survival were 81%, 87% and 82%, respectively. There were no significant differences in any of these end points with respect to IMRT technique (p&gt;0.05 for all). Dosimetric analysis revealed that patients treated by HT had significantly improved salivary sparing with respect to mean dose (27.3 vs 34.1 Gy, p=0.03) and volume receiving greater than or equal to 30 Gy (31.7% vs 47.3%, p=0.01) to the contralateral (spared) parotid gland. The incidence of Grade 3+ late xerostomia was 13 and 7% among patients treated with SMLC-based IMRT and HT, respectively (p=0.62). The corresponding proportion of patients who subjectively reported “too little” or “no” saliva at final follow-up was 38% and 7%, respectively (p=0.04).
Conclusion: The superior dosimetric outcome observed with HT appeared to translate into moderately improved clinical outcomes with respect to salivary sparing. Prospective trials are needed to validate this gain in the therapeutic ratio.
A novel correction factor based on extended volume to complement the conformity index
Authors: Jin F , Wang Y , Wu Y-Z 
Published: February 2012

Objective: We propose a modified conformity index (MCI), based on extended volume, that improves on existing indices by correcting for the insensitivity of previous conformity indices to reference dose shape to assess the quality of high-precision radiation therapy and present an evaluation of its application.
Methods: In this paper, the MCI is similar to the conformity index suggested by Paddick (CIPaddick), but with a different correction factor. It is shown for three cases: with an extended target volume, with an extended reference dose volume and without an extended volume. Extended volume is generated by expanding the original volume by 0.1–1.1 cm isotropically. Focusing on the simulation model, measurements of MCI employ a sphere target and three types of reference doses: a sphere, an ellipsoid and a cube. We can constrain the potential advantage of the new index by comparing MCI with CIPaddick. The measurements of MCI in head–neck cancers treated with intensity-modulated radiation therapy and volumetric-modulated arc therapy provide a window on its clinical practice.
Results: The results of MCI for a simulation model and clinical practice are presented and the measurements are corrected for limited spatial resolution. The three types of MCI agree with each other, and comparisons between the MCI and CIPaddick are also provided.
Conclusion: The results from our analysis show that the proposed MCI can provide more objective and accurate conformity measurement for high-precision radiation therapy. In combination with a dose–volume histogram, it will be a more useful conformity index.
Clinical utility of 18F FDG-PET/CT in the detection of bone marrow disease in Hodgkin's lymphoma
Authors: Muzahir S , Mian M , Munir I , K Nawaz M , S Faruqui Z , A Mufti K , Bashir H , Uddin N , Siddiqui N , U R Maaz A , T Mahmood M 
Published: February 2012

Objective: The aim of the study was to evaluate the potential role of fludeoxyglucose (FDG)-positron emission tomography (PET)/CT in the detection of bone/bone marrow disease in patients with Hodgkin's lymphoma (HL).
Methods: We retrospectively reviewed (18F)-FDG-PET/CT scans of 122 newly diagnosed, biopsy-proven cases of HL performed between November 2009 and June 2010. All the patients were staged before treatment by both PET/CT and bone marrow biopsy (BMB). Patients were subdivided into three groups based on the findings of FDG-PET/CT. Group A consisted of patients showing diffuse FDG uptake, Group B consisted of patients showing unifocal FDG uptake and Group C patients showed multifocal FDG-avid foci on PET/CT scans. Bone marrow results were also reviewed and considered positive if lymphomatous involvement was detected on bone marrow trephine biopsy. BMB results were correlated with FDG-PET/CT findings.
Results: There were 122 patients in total—81 (66.4%) were male and 41 (33.6%) were female. The age range was from 6 years to 78 years (mean 35.70 years). PET/CT was reported as negative for bone/bone marrow involvement in 85 (69.7%) patients, while the remaining 37 showed abnormal FDG uptake. The sensitivity of FDG-PET/CT was calculated to be 100%, the specificity was 76.57%, the negative predictive value was 76.57%, the positive predictive value was 29.72% and the diagnostic accuracy was 78.62%.
Conclusion: 18F-FDG-PET/CT and BMB are complementary in the evaluation of bone marrow disease.