bluuebunny/crossref_metadata_2025 huggingface dataset:
Hamiltonian model of electromechanical actuator in natural reference frame.: Part II: Equations and simulations
Authors: Burlikowski Wojciech
Published: September 2011

Hamiltonian model of electromechanical actuator in natural reference frame.: Part II: Equations and simulations

In the paper a novel mathematical model of electromechanical actuator is presented. It is based on application of Hamiltonian equations in the description of electro-mechanical energy conversion. It results in employment of flux linkages as state variables in the state space equations. For simplicity only a 3-phase wye connected stator winding without a neutral wire is considered in detail. The procedure can be generalised to any number of phases. Topology-based approach is used in the model implementation. Procedures for evaluation of all quantities (currents, energy/coenergy, electro-magnetic torque) present in model equations are described. Eddy currents and hysteresis phenolmenon are neglected in formulation of the model to enable application of state-space description.
Automatic segmentation of radiographic images in industrial applications
Authors: Baniukiewicz Piotr
Published: September 2011

Automatic segmentation of radiographic images in industrial applications

A technology that utilizes penetrating rays is one of the oldest nondestructive testing methods. Nowadays, the process of radiogram analysis is performed by qualified human operators and automatic systems are still under development. In this work we present advanced algorithms for automatic segmentation of radiographic images of welded joints. The goal of segmentation of a radiogram is to change and simplify representation of the image into a form that is more meaningful and easier to analyse automatically. The radiogram is divided into parts containing the weld line, image quality indicators, lead characters, and possible defects. Then, each part is analysed separately by specialized algorithms within the framework of the Intelligent System for Radiogram Analysis.
Influence of work environment on thermal state of electric mine motors
Authors: Krok Roman
Published: September 2011

Influence of work environment on thermal state of electric mine motors

The paper presents a model for calculations of the temperature field in electric mine motors with a water cooled frame. That model was worked out with use of modified and improved thermal networks developed by the author for determining the temperature distributions in different types of ac machines. Thermal calculations for a selected type of 400 kW mining motor were performed with use of an original computer program. Their results were compared with those obtained from measurements. On the basis of the verified simulation results there was determined the influence of value changes of parameters characterising the work environment condition (ambient temperature, inlet temperature and cooling water discharge, degree of covering the casing with coal dust) on the mining motor thermal state.
Smoking, Cognitive Function and Mortality in a U.S. National Cohort Study
Authors: Gillum Richard F. , Kwagyan John , Obisesan Thomas O.
Published: September 2011

Previous studies report that low levels cognitive function and history of smoking are associated with increased mortality risk. Elderly smokers may have increased risk of dementia, but risk in former smokers is unclear. We tested the hypotheses that the harmful effect of impaired cognitive function as related to mortality is greater in persons smoking at baseline than in others. Further, we used serum cotinine levels to assess recall bias of smoking history by cognitive function level. Data were analyzed from a longitudinal mortality follow-up study of 4,916 American men and women aged 60 years and over, examined in 1988–1994 with complete data followed an average 8.5 years. Measurements at baseline included smoking history, a short index of cognitive function (SICF), serum cotinine and socio-demographics. Death during follow-up occurred in 1,919 persons. In proportional hazards regression analysis, a significant interaction of current smoking with cognitive function was not found; but there was a significant age-smoking interaction. After adjusting for confounding by age or multiple variables, current smoking associated with over 2-fold increased mortality (hazards ratio and 95% confidence limits current versus never smoking 2.13, 1.75–2.59) and SICF with 32% reduction in mortality; top versus bottom SICF stratum 0.68, 0.53–0.88). Serum cotinine data revealed substantial recall bias of smoking history in persons with cognitive impairment. However analyses correcting for this bias did not alter the main conclusions: In a nationwide cohort of older Americans, analyses demonstrated a lower risk of death independent of confounders among those with high SICF scores and never smokers, without a significant interaction of the two.
Ultrasmall Peptides Self-Assemble into Diverse Nanostructures: Morphological Evaluation and Potential Implications
Authors: Lakshmanan Anupama , Hauser Charlotte A.E.
Published: September 2011

In this study, we perform a morphological evaluation of the diverse nanostructures formed by varying concentration and amino acid sequence of a unique class of ultrasmall self-assembling peptides. We modified these peptides by replacing the aliphatic amino acid at the C-aliphatic terminus with different aromatic amino acids. We tracked the effect of introducing aromatic residues on self-assembly and morphology of resulting nanostructures. Whereas aliphatic peptides formed long, helical fibers that entangle into meshes and entrap >99.9% water, the modified peptides contrastingly formed short, straight fibers with a flat morphology. No helical fibers were observed for the modified peptides. For the aliphatic peptides at low concentrations, different supramolecular assemblies such as hollow nanospheres and membrane blebs were found. Since the ultrasmall peptides are made of simple, aliphatic amino acids, considered to have existed in the primordial soup, study of these supramolecular assemblies could be relevant to understanding chemical evolution leading to the origin of life on Earth. In particular, we propose a variety of potential applications in bioengineering and nanotechnology for the diverse self-assembled nanostructures.
Studies on the Electrochemical Behavior of Thiazolidine and Its Applications Using a Flow–Through Chronoamperometric Sensor Based on a Gold Electrode
Authors: Wang Lai-Hao , Li Wen-Jie
Published: September 2011

The electrochemical behaviors of thiazolidine (tetrahydrothiazole) on gold and platinum electrodes were investigated in a Britton-Robinson buffer (pH 2.77–11.61), acetate buffer (pH 4.31), phosphate buffer solutions (pH 2.11 and 6.38) and methanol or acetonitrile containing various supporting electrolytes. Detection was based on a gold wire electrochemical signal obtained with a supporting electrolyte containing 20% methanol-1.0 mM of phosphate buffer (pH 6.87, potassium dihydrogen phosphate and dipotassium hydrogen phosphate) as the mobile phase. Comparison with results obtained with a commercial amperometric detector shows good agreement. Using the chronoamperometric sensor with the current at a constant potential, and measurements with suitable experimental parameters, a linear concentration from 0.05 to 16 mg L−1 was found. The limit of quantification (LOQ) of the method for thiazolidine was found to be 1 ng.
Synthesis and Structural Characterization of 1-[2-(5-Nitro-1H-indol-2-yl)phenyl]methylpyridinium Chloride
Authors: Bremner John B. , Samosorn Siritron , Skelton Brian W. , White Allan H.
Published: September 2011

In the course of studies on hybrid antibacterials incorporating 2-aryl-5-nitro-1H-indole moieties as potential bacterial NorA efflux pump inhibitors, the compound 1-[2-(5-nitro-1H-indol-2-yl)phenyl]methylpyridinium chloride (2) was synthesized and structurally characterized. This pyridinium chloride salt crystallized in the monoclinic space group P21/c with the following unit cell dimensions: a 10.274(3) Å, b 13.101(4) Å, c 13.439(4) Å, b 107.702(7)°, V 1723.2(9) Å3, Z (f.u.) = 4; R1 = 0.048, and wR2 = 0.13. Of interest in the single crystal X-ray structure is the (intramolecular) disposition of the pyridinium plane over the indole heterocyclic residue [interplanar dihedral angle 17.91(4)°].
A Novel Anti-Inflammatory Role for Ginkgolide B in Asthma via Inhibition of the ERK/MAPK Signaling Pathway
Authors: Chu Xiao , Ci Xinxin , He Jiakang , Wei Miaomiao , Yang Xiaofeng , Cao Qingjun , Li Hongyu , Guan Shuang , Deng Yanhong , Pang Daxin , Deng Xuming
Published: September 2011

Ginkgolide B is an anti-inflammatory extract of Ginkgo biloba and has been used therapeutically. It is a known inhibitor of platelet activating factor (PAF), which is important in the pathogenesis of asthma. Here, a non-infectious mouse model of asthma is used to evaluate the anti-inflammatory capacity of ginkgolide B (GKB) and characterize the interaction of GKB with the mitogen activated protein kinase (MAPK) pathway. BALB/c mice that were sensitized and challenged to ovalbumin (OVA) were treated with GKB (40 mg/kg) one hour before they were challenged with OVA. Our study demonstrated that GKB may effectively inhibit the increase of T-helper 2 cytokines, such as interleukin (IL)-5 and IL-13 in bronchoalveolar lavage fluid (BALF). Furthermore, the eosinophil count in BALF significantly decreased after treatment of GKB when compared with the OVA-challenged group. Histological studies demonstrated that GKB substantially inhibited OVA-induced eosinophilia in lung tissue and mucus hyper-secretion by goblet cells in the airway. These results suggest that ginkgolide B may be useful for the treatment of asthma and its efficacy is related to suppression of extracellular regulating kinase/MAPK pathway.
Hamlet’s Religions
Authors: Kaufman Peter Iver
Published: September 2011

Pastoral challenges prompted pietists among Elizabethan Catholics and Calvinists to commend what historians now call an inward turn whereby the faithful, in a sense, become their own confessors. This article suggests that spiritual exercises or soliloquies Shakespeare scripted for his Hamlet (and, less so, for Angelo in Measure for Measure) compare favorably with the devotional literature that underscored the importance of self-analysis, intra-psychic conflict, and contrition. The argument here is not that the playwright’s piety resembled his Hamlet’s but that the latter reflected efforts to structure desire in the religions of the time struggling for survival and recognition. References to passages in Shakespeare plays (act, scene) appear parenthetically in the text. Unless otherwise indicated in the bibliography appended to this article, all early printed material is accessible at the Early English Books database, http://eebo.chadwyck.com/home, verified June 1, 2011.
Lattices of Graphical Gaussian Models with Symmetries
Authors: Gehrmann Helene
Published: September 2011

In order to make graphical Gaussian models a viable modelling tool when the number of variables outgrows the number of observations, [1] introduced model classes which place equality restrictions on concentrations or partial correlations. The models can be represented by vertex and edge coloured graphs. The need for model selection methods makes it imperative to understand the structure of model classes. We identify four model classes that form complete lattices of models with respect to model inclusion, which qualifies them for an Edwards–Havránek model selection procedure [2]. Two classes turn out most suitable for a corresponding model search. We obtain an explicit search algorithm for one of them and provide a model search example for the other.
Development and characterization of 10 microsatellite loci in Paeonia lactiflora (Paeoniaceae)
Authors: Sun Jing , Yuan Junxia , Wang Baosheng , Pan Jin , Zhang Daming
Published: September 2011

• Premise of the study: Microsatellite primers were developed in Paeonia lactiflora for further population genetic studies.

• Methods and Results: Ten dinucleotide microsatellite markers were developed using an enriched genomic library. They were identified in 58 individuals, and nine markers were also amplified in its cultivars. The number of alleles per locus ranged from three to 11, with a mean of six. The observed and expected heterozygosities ranged from 0.1662 to 0.9140 and from 0.0841 to 0.8157, respectively.

• Conclusions: These microsatellite markers will facilitate further studies on population genetics variation and genetic structure of P. lactiflora.
Distinguishing magnetic and electrostatic interactions by a Kelvin probe force microscopy–magnetic force microscopy combination
Authors: Jaafar Miriam , Iglesias-Freire Oscar , Serrano-Ramón Luis , Ibarra Manuel Ricardo , de Teresa Jose Maria , Asenjo Agustina
Published: September 2011

The most outstanding feature of scanning force microscopy (SFM) is its capability to detect various different short and long range interactions. In particular, magnetic force microscopy (MFM) is used to characterize the domain configuration in ferromagnetic materials such as thin films grown by physical techniques or ferromagnetic nanostructures. It is a usual procedure to separate the topography and the magnetic signal by scanning at a lift distance of 25–50 nm such that the long range tip–sample interactions dominate. Nowadays, MFM is becoming a valuable technique to detect weak magnetic fields arising from low dimensional complex systems such as organic nanomagnets, superparamagnetic nanoparticles, carbon-based materials, etc. In all these cases, the magnetic nanocomponents and the substrate supporting them present quite different electronic behavior, i.e., they exhibit large surface potential differences causing heterogeneous electrostatic interaction between the tip and the sample that could be interpreted as a magnetic interaction. To distinguish clearly the origin of the tip–sample forces we propose to use a combination of Kelvin probe force microscopy (KPFM) and MFM. The KPFM technique allows us to compensate in real time the electrostatic forces between the tip and the sample by minimizing the electrostatic contribution to the frequency shift signal. This is a great challenge in samples with low magnetic moment. In this work we studied an array of Co nanostructures that exhibit high electrostatic interaction with the MFM tip. Thanks to the use of the KPFM/MFM system we were able to separate the electric and magnetic interactions between the tip and the sample.
Recherche d'informations auprès d'autrui et en dehors d'internet chez les cyberétudiants : rôle du soutien social perçu
Authors: Vayre Émilie , Dupuy Raymond , Croity-Belz Sandrine
Published: September 2011

Notre étude vise à décrire et expliquer la diversité des démarches de sollicitation d’autrui développées par les étudiants en fonction de dispositifs de formation différenciés par leur degré d’intégration des TIC (face-à-face vs e-learning). Toutefois, nous postulons que cette relation n’est pas linéaire mais modulée par le soutien social perçu par les étudiants. Les résultats de notre enquête menée par questionnaire auprès de 195 étudiants vont dans le sens de notre hypothèse. Ils soulignent notamment que, chez les cyberétudiants, le soutien social provenant des pairs revêt une importance particulière dans la mise en œuvre de comportements relationnels de recherche d’informations en face-à-face et par téléphone auprès des enseignants de la formation.
Evidence-Based Practice for Staff Nurses
Authors: Grant Marcia , Hanson Jo , Johnson Shirley , Idell Cynthia , Rutledge Dana N.
Published: September 2011

Background:

Barriers to the involvement of staff nurses in evidence-based practice include time commitments, staffing challenges, and limited experience in identifying evidence.

Methods:

A 1-day, hands-on course focused on small, achievable, evidence-based practice projects; follow-up after the course by a project director; and commitment to implementation of participants’ projects by management. Faculty included a librarian who helped with computer searches and a quality assurance representative to facilitate availability of institutional data for project evaluation.

Results:

Nine courses held over a 3-year period involved 79 home institution nurses and 76 community nurses. Course evaluations were overwhelmingly positive. Completed projects were displayed on participants’ units and circulated throughout the institution. The courses are continuing as part of the regular annual nursing education calendar.

Conclusion:

Streamlined approaches to teaching evidence-based practice can be used to involve staff nurses and raise awareness of evidence-based practice across nursing. Key positive findings include achievable projects, provisions for follow-up, and management support.
The Use of the Lotus Position During Spica Cast Application for the Treatment of Developmental Dysplasia of the Hip: A Technical Note
Authors: Keren Yaniv , Sadia Shadi , Eidelman Mark
Published: September 2011

Closed reduction and application of a spica cast is a standard treatment in children younger than 18 months. Proper abduction and flexion is crucial during cast application. The surgeon, who usually stands holding the lower limbs, often finds this position cumbersome and difficult to control limb position. During the past 6 years, we have used the lotus (crossed legs) position for the surgeon to achieve better control on hip flexion and abduction, therefore minimizing possible complications such as osteonecrosis of the femoral head.
Comparison of Non-Contact Methods for the Measurement of Central Corneal Thickness
Authors: Gorgun Ebru , Yenerel Nursal Melda , Dinc Umut Asli , Oncel Banu , Kucumen Raciha Beril , Oral Deniz , Ciftci Ferda
Published: September 2011

BACKGROUND AND OBJECTIVE:

This study examined the repeatability of and agreements between central corneal thickness measurements obtained by four different non-contact pachymetry devices.

PATIENTS AND METHODS:

Seventy-eight eyes of 39 subjects were included. Central corneal thickness of each eye was measured by Visante optical coherence tomography (OCT) (Carl Zeiss Meditec Inc., Dublin, CA), Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany), Orbscan IIz topography (Bausch & Lomb Surgical Inc., San Dimas, CA), and slit-lamp OCT (SL-OCT) (Heidelberg Engineering GmbH, Heidelberg, Germany). Inter-device agreements and correlations and repeatability of each device were examined.

RESULTS:

All measurement methods correlated well with each other with a correlation coefficient greater than 0.90 and
P
value of less than .001 for all comparisons. However, Pentacam overestimated central corneal thickness: 546.7 ± 38.2, 535.5 ± 42.7, 531.7 ± 37.6, and 531.2 ± 36.0 μm for Pentacam, Orbscan IIz, Visante OCT, and SL-OCT, respectively (
P
< .001 for all comparisons versus Pentacam). Despite good correlation, magnitude of differences was high and this bias was proportional (ie, not constant across a range of corneal thickness values) for the following pairs: Orbscan versus Visante OCT, Orbscan versus SL-OCT, and Orbscan versus Pentacam (
P
< .001 for all comparisons).

CONCLUSION:

Although measurements obtained by various non-contact methods correlate well, numerical agreement of the results may not be sufficient for their interchangeable use in clinical practice.
Comparison of Complication Rates of Porous Anophthalmic Orbital Implants
Authors: Ramey Nicholas , Gupta Divakar , Price Kristina , Husain Amina , Richard Michael , Woodward Julie
Published: September 2011

BACKGROUND AND OBJECTIVE:

Porous anophthalmic orbital implants are used widely. This study evaluates risk factors for porous anophthalmic orbital implant complications and compares complication rates of hydroxyapatite, porous polyethylene, and polyglactin mesh-wrapped aluminum oxide implants.

PATIENTS AND METHODS:

The records of 105 patients (110 eyes) who received porous anophthalmic orbital implants for any indication were reviewed retrospectively. Complications were recorded and correlated with potential risk factors, including implant material. All patient records were de-identified to protect privacy.

RESULTS:

Porous polyethylene and aluminum oxide implants were associated with higher exposure rates (porous polyethylene: odds ratio 6.1 [1.29, 29.1]; aluminum oxide: odds ratio 6.0 [1.58, 23.1];
P
= .004) and higher overall complication rates compared to hydroxyapatite implants.

CONCLUSION:

Implant material may be a risk factor for several anophthalmic clinical outcomes.
Retinopathy Associated With Pegylated Interferon and Ribavirin Causing Permanent Visual Impairment in a Patient With Chronic Hepatitis C
Authors: Moisseiev Elad , Goldenberg Dafna , Kurtz Shimon
Published: September 2011

Retinopathy associated with pegylated interferon and ribavirin is a known complication of this therapy, and is typically bilateral and asymptomatic. Few patients complain of visual disturbance, and only rarely is there permanent visual impairment after the retinopathy resolves. A 65-year-old man presented with bilateral reduced visual acuity. Treatment with pegylated interferon and ribavirin was initiated 12 weeks prior due to chronic hepatitis virus C. On examination, multiple cotton-wool spots were noticed bilaterally, and visual field testing demonstrated decreased sensitivity. Treatment was stopped and the retinopathy was followed up for 4 months by ophthalmic examination and high-resolution optical coherence tomography. The cotton-wool spots resolved and high-resolution optical coherence tomography demonstrated restoration of normal retinal configuration. Visual acuity and visual field testing improved over 4 months, but did not return to their baseline values. This is a rare case of permanent visual impairment caused by retinopathy associated with pegylated interferon and ribavirin.
Estimación de la masa corporal en géneros del Orden Notoungulata
Authors: Elissamburu A.
Published: September 2011

Los Notoungulata son un grupo de mamíferos fósiles ampliamente diversos y sin representantes vivientes. Prácticamente no se disponen de estimaciones de la masa corporal para la mayoría de los géneros incluidos en este Orden, ni de un método objetivo para seleccionar los estimadores de masa. El objetivo del trabajo es estimar la masa corporal de los representantes del Orden Notoungulata y reconocer cuales son las mejores ecuaciones predictivas para tal fin, respecto a cada taxón en particular, a cada familia y al Orden en general. Se incluyen 535 ejemplares fósiles correspondientes a 50 géneros del orden. La masa corporal de cada género se estima sobre la base de 24 ecuaciones alométricas construidas en mamíferos vivientes, basadas en 19 medidas del esqueleto apendicular y tres medidas dentarias tomadas con calibre digital. El intervalo de masa corporal dado por los valores estimados para el orden se encuentra entre 0,57 kg en Archaeophylus (Interatheriidae) y 3797 Kg en Mixotoxodon (Toxodontidae), lo que refleja la gran diversidad de tamaños corporales que caracteriza al grupo. Los menores tamaños se dan en las familias Notostylopidae, Oldfieldthomasiidae, Archaeopithecidae, Interatheriidae, Archaeohyracidae y Hegetotheriidae; tamaños intermedios en los Notohippidae, Isotemnidae y Mesotheriidae y tamaños grandes en Homalodotheriidae. En los Leontiniidae y Toxodontidae los tamaños van de intermedios a grandes, siendo esta última la de mayor variación de masa y con los taxones de mayor tamaño. En comparación con los ungulados holárticos, los notoungulados presentan un intervalo más amplio y variable de masa corporal hacia las formas de menor tamaño y con mayor variedad funcional en las extremidades.
Génesis de la estructura arqueada de la Sierra de las Cabras al Gibalto (Subbético, provincias de Málaga y Granada, España)
Authors: Sanz de Galdeano C.
Published: September 2011

Las sierras subbéticas de las Cabras al Gibalto forman una estructura arqueada, que da un fuerte relieve, constituida por escamas tectónicas, vergentes al sur en su borde convexo, meridional, y al nor-te y oeste en su borde cóncavo. Aunque podría interpretarse como una estructura alóctona, se en-cuentra enraizada en el área de tránsito entre el Subbético Medio y el Interno. En su génesis han in-fluido varios factores locales pero la causa que controla a todos ellos es la colisión oblicua, en trans-presión, de la Zona Interna Bética contra la Externa, que produjo un importante sistema de desgarre.
Generalized linear Bayesian models for standardizing CPUE: an application to a squid-jigging fishery in the northwest Pacific Ocean
Authors: Cao Jie , Chen Xinjun , Chen Yong , Liu Bilin , Ma Jin , Li Siliang
Published: September 2011

Generalized linear Bayesian (GLBM) non-hierarchical and hierarchical models were developed for standardization of catch per unit effort (CPUE). The GLBM containing the covariates of month, latitude, sea surface temperature (SST), sea surface salinity (SSS) and sea level height (SLH) had the best fit for the Chinese squid-jigging fishery of Ommastrephes bartramii in the northwest Pacific Ocean based on deviance information criteria. This best-fitting model tends to be more ecologically sound than other CPUE standardization models, such as generalized linear models and generalized additive models. GLBM was also used to deal with the problems of estimating stock abundance index (i.e. standardized CPUE) resulting from increased spatial heterogeneity of spatial dynamics of fishing efforts in the squid fishery by predicting the standardized CPUE for unfished areas. The standardized CPUE based on data including predicted CPUE of unfished areas was lower than the derived CPUE based on data with observed CPUE alone, in particular during the fishing peak of August to October. This study indicates that it is more appropriate to use the standardized CPUE derived from data including both predicted CPUE of unfished areas and observed CPUE of fished area as a stock abundance index. We suggest that the proposed method be used in CPUE standardization to account for impacts of large spatial heterogeneity of fishing efforts in fisheries.
Balearic Islands vs Algeria: two nearby western Mediterranean elasmobranch assemblages with different oceanographic scenarios and fishing histories
Authors: Ordines Francesc , Massutí Enric , Moranta Joan , Quetglas Antoni , Guijarro Beatriz , Fliti Khaled
Published: September 2011

In this paper we compare the elasmobranch composition, depth-related trends of species and community descriptors (abundance, biomass, mean fish weight, species richness and diversity) of the Balearic Islands Archipelago and Algeria (north- and southwestern Mediterranean, respectively). The samples used in this study were collected in bottom trawl surveys between 36 and 779 m depth. Generalized linear models, linear regression, cluster and similarity percentage analyses, and generalized additive models were used to compare the two areas. Twenty-nine elasmobranch species were caught, 12 of them common to both areas, 7 appearing only in the Balearic Islands, and 10 only in Algeria. The bathymetric distributions of species were, in most cases, best fitted to uni-modal response curves. The models for species common to both areas showed similar bathymetric trends, except for Etmopterus spinax, which in Algeria showed a maximum abundance located 154 m shallower than in the Balearic Islands. Four bathymetric assemblages were identified in both areas with similar depth ranges but with different species composition. The mean values of the community descriptors were higher on the shelf in the Balearic Islands, whereas higher values were detected on the slope in Algeria. Different between-area bathymetric trends for all the descriptors were detected, with the exception of mean fish weight. The distinct environmental scenarios and fishing histories of the areas studied are discussed as underlying traits influencing the elasmobranch populations.
Effect of Age and Lordotic Angle on the Level of Lumbar Disc Herniation
Authors: Skaf Ghassan S. , Ayoub Chakib M. , Domloj Nathalie T. , Turbay Massud J. , El-Zein Cherine , Hourani Mukbil H.
Published: September 2011

It has been previously suggested in the literature that with aging, degenerative changes as well as disc herniation start at the lower lumbar segments, with higher disc involvement observed in an ascending fashion in older age groups. We conducted a study to investigate this correlation between age and level of disc herniation, and to associate it with the magnitude of the Lumbar Lordotic Angle (LLA), as measured by Cobb’s method. We followed retrospectively lumbosacral spine MRI’s of 1419 patients with symptomatic disc herniation. Pearson’s correlation was used in order to investigate the relationship between LLA, age, and level of disc herniation. Student’s -test was applied to assess gender differences. Young patients were found to have higher LLA (, ) and lower levels of disc herniation (, ), whereas older patients had higher level herniation in lower LLA group (mean LLA 28.6° and 25.4°) and lower level herniation in high LLA group (mean LLA 33.2°). We concluded that Lumbar lordotic Cobb’s angle and age can be predictors of the level of lumbar disc herniation. This did not differ among men and women (, ).
Evaluation of Patient Renal Function Following Endovascular Aneurysm Repair with Suprarenal Fixation
Authors: Jia YingBin , Shi Yun , Guan XiaoDong , Li Jian , Zhang BaiMeng , Fu WeiGuo
Published: September 2011

This study aimed to assess the mid-term renal function of abdominal aortic aneurysm patients following suprarenal endovascular repair. From March 2005 to December 2009, 290 abdominal aortic aneurysm patients were included in the study and grouped according to whether they had received infrarenal or suprarenal endovascular aneurysm repair. Suprarenal endovascular aneurysm repair was performed in 173 patients, with a mean age of 72(±8) years (85.0% male). Infrarenal endovascular aneurysm repair was performed in 117 patients, with a mean age of 71(±9) years (90.6% male). Preoperative and one week, 1-, 3-, 6- and 12-month postoperative serum creatinine and cystatin C values were recorded. Estimated glomerular filtration rate was calculated by cystatin-based formula and Cr-based Cockcroft formula. The t-test was used to determine statistical differences between or within groups. All patients received Talent or Zenith endograft. Patients’ characteristics and operative files in the two groups were well matched. Preoperative serum creatinine and cystatin C were 82 (±8) mmol/L and 0.89 (±0.11) mg/L for suprarenal endovascular aneurysm repair, respectively, and 81 (±11) mmol/L and 0.87 (±0.15) mg/L, respectively, for infrarenal endovascular aneurysm repair; no differences were observed between the two groups. Compared to preoperative renal markers within each group, a deterioration in serum creatinine, cystatin C and estimated glomerular filtration rate values was found at one week and 12 months after surgery（p < 0.05). A deterioration in cystatin C [SR:(0.93 ± 0.17) mg/L, IR: (0.92 ± 0.31) mg/L] and estimated glomerular filtration rate by cystatin C was also found at six months after surgery（p < 0.05). However, no differences in patient serum creatinine, cystatin C and estimated glomerular filtration rate values were observed between groups at each follow-up time interval. There was no greater significant difference in the association of the use of suprarenal fixation with midterm postoperative renal injury than with infrarenal fixation.
The Renormalization Group
Authors: Disertori Margherita , Feldman Joel , Salmhofer Manfred
Published: September 2011

Invented as a multiscale approach to the theory of critical phenomena, the renormalization group has become a powerful mathematical tool in the analysis of infinite-dimensional systems. Its applications range from classical and quantum statistical mechanics and quantum field theory to partial differential equations, operator theory, and probability theory. Deep connections of renormalization group flows to geometric flows exist.
Operator Algebras and Representation Theory: Frames, Wavelets and Fractals
Authors: Jorgensen Palle E.T. , Kutyniok Gitta , Olafsson Gestur , Silvestrov Sergei
Published: September 2011

The central focus of the workshop was Kadison-Singer conjecture and its connection to operator algebras, harmonic analysis, representation theory and the theory of fractals. The program was intrinsically interdisciplinary and represented areas with much recent progress. The workshop includes talks on operator theory, wavelets, shearlets, frames, fractals, representations theory and compressed sensing.
Adaptive Finite Element Modeling Techniques for the Poisson-Boltzmann Equation
Authors: Holst M. , McCammon J.A. , Yu Z. , Zhou Y.C. , Zhu Y.
Published: September 2011

We consider the design of an effective and reliable adaptive finite element method (AFEM) for the nonlinear Poisson-Boltzmann equation (PBE). We first examine the two-term regularization technique for the continuous problem recently proposed by Chen, Holst and Xu based on the removal of the singular electrostatic potential inside biomolecules; this technique made possible the development of the first complete solution and approximation theory for the Poisson-Boltzmann equation, the first provably convergent discretization and also allowed for the development of a provably convergent AFEM. However, in practical implementation, this two-term regularization exhibits numerical instability. Therefore, we examine a variation of this regularization technique which can be shown to be less susceptible to such instability. We establisha prioriestimates and other basic results for the continuous regularized problem, as well as for Galerkin finite element approximations. We show that the new approach produces regularized continuous and discrete problems with the same mathematical advantages of the original regularization. We then design an AFEM scheme for the new regularized problem and show that the resulting AFEM scheme is accurate and reliable, by proving a contraction result for the error. This result, which is one of the first results of this type for nonlinear elliptic problems, is based on using continuous and discretea prioriL∞estimates. To provide a high-quality geometric model as input to the AFEM algorithm, we also describe a class of feature-preserving adaptive mesh generation algorithms designed specifically for constructing meshes of biomolecular structures, based on the intrinsic local structure tensor of the molecular surface. All of the algorithms described in the article are implemented in the Finite Element Toolkit (FETK), developed and maintained at UCSD. The stability advantages of the new regularization scheme are demonstrated with FETK through comparisons with the original regularization approach for a model problem. The convergence and accuracy of the overall AFEMalgorithmis also illustrated by numerical approximation of electrostatic solvation energy for an insulin protein.
Modeling Ionic Polymer-Metal Composites with Space-Time Adaptive Multimeshhp-FEM
Authors: Pugal David , Solin Pavel , Kim Kwang J. , Aabloo Alvo
Published: September 2011

We are concerned with a model of ionic polymer-metal composite (IPMC) materials that consists of a coupled system of the Poisson and Nernst-Planck equations, discretized by means of the finite element method (FEM). We show that due to the transient character of the problem it is efficient to use adaptive algorithms that are capable of changing the mesh dynamically in time. We also show that due to large qualitative and quantitative differences between the two solution components, it is efficient to approximate them on different meshes using a novel adaptive multimeshhp-FEM. The study is accompanied with numerous computations and comparisons of the adaptive multimeshhp-FEM with several other adaptive FEM algorithms.
A Preconditioned Implicit Free-Surface Capture Scheme for Large Density Ratio on Tetrahedral Grids
Authors: Lv Xin , Zou Qingping , Reeve D.E. , Zhao Yong
Published: September 2011

We present a three dimensional preconditioned implicit free-surface capture scheme on tetrahedral grids. The current scheme improves our recently reported method [10] in several aspects. Specifically, we modified the original eigensystem by applying a preconditioning matrix so that the new eigensystem is virtually independent of density ratio, which is typically large for practical two-phase problems. Further, we replaced the explicit multi-stage Runge-Kutta method by a fully implicit Euler integration scheme for the Navier-Stokes (NS) solver and the Volume of Fluids (VOF) equation is now solved with a second order Crank-Nicolson implicit scheme to reduce the numerical diffusion effect. The preconditioned restarted Generalized Minimal RESidual method (GMRES) is then employed to solve the resulting linear system. The validation studies show that with these modifications, the method has improved stability and accuracy when dealing with large density ratio two-phase problems.
Mixed Multiscale Finite Volume Methods for Elliptic Problems in Two-Phase Flow Simulations
Authors: Jiang Lijian , Mishev Ilya D.
Published: September 2011

We develop a framework for constructing mixed multiscale finite volume methods for elliptic equations with multiple scales arising from flows in porous media. Some of the methods developed using the framework are already known [20]; others are new. New insight is gained for the known methods and extra flexibility is provided by the new methods. We give as an example a mixed MsFV on uniform mesh in 2-D. This method uses novel multiscale velocity basis functions that are suited for using global information, which is often needed to improve the accuracy of the multiscale simulations in the case of continuum scales with strong non-local features. The method efficiently captures the small effects on a coarse grid. We analyze the new mixed MsFV and apply it to solve two-phase flow equations in heterogeneous porous media. Numerical examples demonstrate the accuracy and efficiency of the proposed method for modeling the flows in porous media with non-separable and separable scales.
A Bistable Field Model of Cancer Dynamics
Authors: Cherubini C. , Gizzi A. , Bertolaso M. , Tambone V. , Filippi S.
Published: September 2011

Cancer spread is a dynamical process occurring not only in time but also in space which, for solid tumors at least, can be modeled quantitatively by reaction and diffusion equations with a bistable behavior: tumor cell colonization happens in a portion of tissue and propagates, but in some cases the process is stopped. Such a cancer proliferation/extintion dynamics is obtained in many mathematical models as a limit of complicated interacting biological fields. In this article we present a very basic model of cancer proliferation adopting thebistableequation for a single tumor cell dynamics. The reaction-diffusion theory is numerically and analytically studied and then extended in order to take into account dispersal effects in cancer progression in analogy with ecological models based on the porous medium equation. Possible implications of this approach for explanation and prediction of tumor development on the lines of existing studies on brain cancer progression are discussed. The potential role of continuum models in connecting the two predominant interpretative theories about cancer, once formalized in appropriate mathematical terms, is discussed.
Cloud base vertical velocity statistics: a comparison between an atmospheric mesoscale model and remote sensing observations
Authors: Tonttila J. , O'Connor E. J. , Niemelä S. , Räisänen P. , Järvinen H.
Published: September 2011

Abstract. The statistics of cloud base vertical velocity simulated by the non-hydrostatic mesoscale model AROME are compared with Cloudnet remote sensing observations at two locations: the ARM SGP site in central Oklahoma, and the DWD observatory at Lindenberg, Germany. The results show that AROME significantly underestimates the variability of vertical velocity at cloud base compared to observations at their nominal resolution; the standard deviation of vertical velocity in the model is typically 4–8 times smaller than observed, and even more during the winter at Lindenberg. Averaging the observations to the horizontal scale corresponding to the physical grid spacing of AROME (2.5 km) explains 70–80 % of the underestimation by the model. Further averaging of the observations in the horizontal is required to match the model values for the standard deviation in vertical velocity. This indicates an effective horizontal resolution for the AROME model of at least 10 km in the presented case. Adding a TKE-term on the resolved grid-point vertical velocity can compensate for the underestimation, but only for altitudes below approximately the boundary layer top height. The results illustrate the need for a careful consideration of the scales the model is able to accurately resolve, as well as for a special treatment of sub-grid scale variability of vertical velocities in kilometer-scale atmospheric models, if processes such as aerosol-cloud interactions are to be included in the future.
Airborne DOAS measurements in Arctic: vertical distributions of aerosol extinction coefficient and NO2 concentration
Authors: Merlaud A. , Van Roozendael M. , Theys N. , Fayt C. , Hermans C. , Quennehen B. , Schwarzenboeck A. , Ancellet G. , Pommier M. , Pelon J. , Burkhart J. , Stohl A. , De Mazière M.
Published: September 2011

Abstract. We report on airborne Differential Optical Absorption Spectroscopy (DOAS) measurements of aerosol extinction and NO2 tropospheric profiles performed off the North coast of Norway in April 2008. The DOAS instrument was installed on the Safire ATR-42 aircraft during the POLARCAT-France spring campaign and recorded scattered light spectra in near-limb geometry using a scanning telescope. We use O4 slant column measurements to derive the aerosol extinction at 360 nm. Regularization is based on the maximum a posteriori solution, for which we compare a linear and a logarithmic approach. The latter inherently constrains the solution to positive values and yields aerosol extinction profiles more consistent with independently measured size distributions. We present results from two soundings performed on 8 April 2008 above 71° N, 22° E and on 9 April 2008 above 70° N, 17.8° E. The first profile shows aerosol extinction and NO2 in the marine boundary layer with respective values of 0.04 ± 0.005 km−1 and 1.9 ± 0.3 × 109 molec cm−3. A second extinction layer of 0.01 ± 0.003 km−1 is found at 4 km altitude where the NO2 concentration is 0.32 ± 0.2 × 109 molec cm−3. During the second sounding, clouds prevent retrieval of profile parts under 3 km altitude but a layer with enhanced extinction (0.025 ± 0.005 km−1) and NO2 (1.95 ± 0.2 × 109 molec cm−3) is clearly detected at 4 km altitude. From CO and ozone in-situ measurements complemented by back-trajectories, we interpret the measurements in the free troposphere as, for the first sounding, a mix between stratospheric and polluted air from Northern Europe and for the second sounding, polluted air from Central Europe containing NO2. Considering the boundary layer measurements of the first flight, modeled source regions indicate closer sources, especially the Kola Peninsula smelters, which can explain the NO2 enhancement not correlated with a CO increase at the same altitude.
Further analyses of the decadal-scale responses and trends in middle and upper stratospheric ozone from SAGE II and HALOE
Authors: Remsberg E. E.
Published: September 2011

Abstract. Stratospheric Aerosol and Gas Experiment (SAGE II) Version 6.2 ozone profiles are analyzed for their decadal-scale responses and linear trends in the middle and upper stratosphere from 1984 through 1998. The results are compared with those of SAGE II and of the Halogen Occultation Experiment (HALOE) for 1991–2005, reported previously by Remsberg and Lingenfelser (2010). The regression model fit to the data includes a periodic 11- term, and it is in-phase with that of the 11-yr solar uv-flux throughout most of the latitude/altitude domain of the middle and upper stratosphere. Max minus min responses for the upper stratosphere are of order 2% from the HALOE time series that are in terms of mixing ratio versus pressure. Max minus min responses are of order 4% from SAGE II in terms of number density versus altitude and for both 1984–1998 and 1991–2005, even though the concurrent linear trend term coefficients are much different for the two time spans. However, the analyzed 11-yr response from the SAGE II data of 1984–1998 lags that of the uv-flux by 1 to 2 yr in the tropical middle stratosphere, most likely due to the effects of ENSO forcings that are not represented in the regression models. The linear ozone trends in the upper stratosphere for 1991 to 2005 are of the order of −2 to −3%/decade from SAGE II and 0 to −1%/decade from HALOE. Those differences in the ozone trends must be principally due to the associated temperature trends for the analyzed data.
An aircraft based three channel broadband cavity enhanced absorption spectrometer for simultaneous measurements of NO3, N2O5 and NO2
Authors: Kennedy O. J. , Ouyang B. , Langridge J. M. , Daniels M. J. S. , Bauguitte S. , Freshwater R. , McLeod M. W. , Ironmonger C. , Sendall J. , Norris O. , Nightingale R. , Ball S. M. , Jones R. L.
Published: September 2011

Abstract. A three channel broadband cavity enhanced absorption spectroscopy (BBCEAS) instrument has been developed for airborne measurements of atmospheric trace gases involved in night-time oxidation chemistry and air quality. The instrument was deployed on board the Facility for Airborne Atmospheric Measurements BAe 146-301 atmospheric research aircraft during the Role of Nighttime Chemistry in Controlling the Oxidising Capacity of the Atmosphere (RONOCO) measurement campaigns between December 2009 and January 2011. In its present configuration (i.e. specifications of the cavity optics and spectrometers) the instrument is designed to measure NO3, N2O5 (by detection of NO3 after thermal dissociation of N2O5), H2O and NO2 by characterising the wavelength dependent optical attenuation within ambient samples by molecular absorption around 662 nm (NO3 and H2O) and 445 nm (NO2). This paper reports novel advancements in BBCEAS instrumentation including a refined method for performing BBCEAS mirror reflectivity calibrations using measurements of the phase delay introduced by the optical cavities to amplitude modulated radiation. Furthermore, a new methodology is introduced for fitting the strong but unresolved transitions of water vapour, which is required for accurate retrieval of water absorption features from the 662 nm absorption band used to measure NO3 concentrations. The paper also details the first example of airborne measurements of NO3, N2O5 and NO2 over Europe from a flight over the North Sea and Thames Estuary on the night of the 20 July 2010, one of the most polluted days of the RONOCO summertime flying period. As part of this analysis, the performance of the BBCEAS instrument is assessed by comparing airborne NO2 measurements to those reported concurrently by a photolytic chemiluminescence based detector.
Cinema on Cinema: The Kinship between Cinema Paradiso and Zıkkımın Kökü, Karpuz Kabuğundan Gemiler Yapmak, Sinema Bir Mucizedir
Authors: Demiray Basak
Published: September 2011

This study consists of a comparative analysis of four films which fall under the category of “cinema on cinema”. These films are Cinema Paradiso (Giuseppe Tornatore, 1988, Italy), Zıkkımın Kökü (Memduh Ün, 1993, Turkey), Karpuz Kabuğundan Gemiler Yapmak/ Boats out of Watermelon Rinds ( Ahmet Uluçay, 2004, Turkey), Sinema Bir Mucizedir/ Cinema is a Miracle (Memduh Ün- Tunç Başaran, 2005, Turkey). It will be argued that these films have four main points of similarity. First, they are the instances of “cinema on cinema”; second, they are biographical films; third, their plots are constructed upon the rural lives of the past; fourth, they are about cinephilia.