bluuebunny/crossref_metadata_2025 huggingface dataset:
Epidemics as Markers of Socio-economic Inequalities
Authors: Baru Rama V.
Published: October 2011

The last two decades have been marked by sustained economic growth with the persistence and in some cases widening of regional and socio-economic inequalities. The resurgence of infectious diseases is a marker of these growing inequalities and poor public health services in India.
Safety of long-term treatment of HAM/TSP patients with valproic acid
Authors: Olindo Stéphane , Belrose Gildas , Gillet Nicolas , Rodriguez Sabrina , Boxus Mathieu , Verlaeten Olivier , Asquith Becca , Bangham Charles , Signaté Aïssatou , Smadja Didier , Lezin Agnès , Césaire Raymond , Willems Luc
Published: October 2011

HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a neurodegenerative disease of the central nervous system induced by human T-lymphotropic virus type 1. As a potential therapeutic approach, we previously suggested reducing the proviral load by modulating lysine deacetylase activity using valproic acid (VPA) and exposing virus-positive cells to the host immune response. We conducted a single-center, 2-year, open-label trial, with 19 HAM/TSP volunteers treated with oral VPA. Proviral load, CD38/HLA-DR expression, and CD8+ lysis efficiency were not significantly affected by VPA. Mean scores of HAM/TSP disability did not differ between baseline and final visit. Walking Time Test increased significantly (> 20%) in 3 patients and was in keeping with minor VPA side effects (drowsiness and tremor). Walking Time Test improved rapidly after VPA discontinuation. We conclude that long-term treatment with VPA is safe in HAM/TSP.
Definitions of histocompatibility typing terms
Authors: Nunes Eduardo , Heslop Helen , Fernandez-Vina Marcelo , Taves Cynthia , Wagenknecht Dawn R. , Eisenbrey A. Bradley , Fischer Gottfried , Poulton Kay , Wacker Kara , Hurley Carolyn Katovich , Noreen Harriet , Sacchi Nicoletta
Published: October 2011

Histocompatibility testing for stem cell and solid organ transplantation has become increasingly complex as newly discovered HLA alleles are described. HLA typing assignments reported by laboratories are used by physicians and donor registries for matching donors and recipients. To communicate effectively, a common language for histocompatibility terms should be established. In early 2010, representatives from Clinical, Registry, and Histocompatibility organizations joined together as the Harmonization of Histocompatibility Typing Terms Working Group to define a consensual language for laboratories, physicians, and registries to communicate histocompatibility typing information. The Working Group defined terms for HLA typing resolution, HLA matching, and a format for reporting HLA assignments. In addition, definitions of verification typing and extended typing were addressed. The original draft of the Definitions of Histocompatibility Typing Terms was disseminated to colleagues from each organization to gain feedback and create a collaborative document. Commentary gathered during this 90-day review period were discussed and implemented for preparation of this report. Histocompatibility testing continues to evolve; thus, the definitions agreed on today probably will require refinement and perhaps additional terminology in the future.
Searching and Learning by Trial and Error
Authors: Callander Steven
Published: October 2011

I study a dynamic model of trial-and-error search in which agents do not have complete knowledge of how choices are mapped into outcomes. Agents learn about the mapping by observing the choices of earlier agents and the outcomes that are realized. The key novelty is that the mapping is represented as the realized path of a Brownian motion. I characterize for this environment the optimal behavior each period as well as the trajectory of experimentation and learning through time. Applied to new product development, the model shares features of the data with the well-known Product Life Cycle. (JEL D81, D83, D92, L26)
Private Monitoring and Communication in Cartels: Explaining Recent Collusive Practices
Authors: Harrington Joseph E , Skrzypacz Andrzej
Published: October 2011

Motivated by recent cartel practices, a stable collusive agreement is characterized when firms' prices and quantities are private information. Conditions are derived whereby an equilibrium exists in which firms truthfully report their sales and then make transfers within the cartel based on these reports. The properties of this equilibrium fit well with the cartel agreements in a number of markets including citric acid, lysine, and vitamins. (JEL D43, D82, K21, L12, L61, L65)
The Sense and Non-Sense of Holdout Sample Validation in the Presence of Endogeneity
Authors: Ebbes Peter , Papies Dominik , van Heerde Harald J.
Published: October 2011

Market response models based on field-generated data need to address potential endogeneity in the regressors to obtain consistent parameter estimates. Another requirement is that market response models predict well in a holdout sample. With both requirements combined, it may seem reasonable to subject an endogeneity-corrected model to a holdout prediction task, and this is quite common in the academic marketing literature. One may be inclined to expect that the consistent parameter estimates obtained via instrumental variables (IV) estimation predict better than the biased ordinary least squares (OLS) estimates. This paper shows that this expectation is incorrect. That is, if the holdout sample is similar to the estimation sample so that the regressors are endogenous in both samples, holdout sample validation favors regression estimates that are not corrected for endogeneity (i.e., OLS) over estimates that are corrected for endogeneity (i.e., IV estimation). We also discuss ways in which holdout samples may be used sensibly in the presence of endogeneity. A key takeaway is that if consistent parameter estimates are the primary model objective, the model should be validated with an exogenous (rather than endogenous) holdout sample.
Simultaneous Detection of High-Sensitivity Cardiac Troponin I and Myoglobin by Modified Sandwich Lateral Flow Immunoassay: Proof of Principle
Authors: Zhu Jimin , Zou Nengli , Zhu Danian , Wang Jin , Jin Qinghui , Zhao Jianlong , Mao Hongju
Published: October 2011

BACKGROUND

Although numerous lateral flow immunoassays (LFIAs) have been developed and widely used, inadequate analytical sensitivity and the lack of multiple protein detection applications have limited their clinical utility. We developed a new LFIA device for the simultaneous detection of high-sensitivity cardiac troponin I (hs-cTnI) and myoglobin (Myo).

METHODS

We used a gold nanoparticle (AuNP) doubly labeled complex, in which biotinylated single-stranded DNA was used as a linkage to integrate 2 AuNPs and streptavidin-labeled AuNP, as an amplifier to magnify extremely low signals.

RESULTS

The detection limit of 1 ng/L achieved for hs-cTnI was 1000 times lower than that obtained in a conventional LFIA. The detection limit for simultaneously measured Myo was 1 μg/L. The linear measurement ranges for hs-cTnI and Myo were 1–10 000 ng/L and 1–10 000 μg/L, respectively. We observed concordant results between the LFIA and clinical assays in sera from 12 patients with acute myocardial infarction (hs-cTnI r = 0.96; Myo r = 0.98). Assay imprecision was <11% for both hs-TnI and myo.

CONCLUSIONS

The described proof-of-principle LFIA method could be used as a point-of-care device in multiple protein quantification and semiquantitative analysis.
Consonant lenition and phonological recategorization
Authors: Hualde José Ignacio , Simonet Miquel , Nadeu Marianna
Published: October 2011

We examine the weakening of intervocalic voiceless stops in Spanish in order to gain insight on historical processes of intervocalic lenition. In our corpus, about a third of all tokens of intervocalic /ptk/ are fully or partially voiced in spontaneous speech. However, even when fully voiced, /ptk/ tend to show greater constriction than /bdg/, with the velars being less different than labials and coronals. Word-initial and word-internal intervocalic segments are equally affected. Based on our findings from acoustic measurements of correlates of lenition, we propose that common reductive sound changes, such as intervocalic consonant lenition, start as across-the-board conventionalized phonetic processes equally affecting all targets in the appropriate phonetic context. The common restriction of the sound change to word-internal contexts may be a consequence of phonological recategorization at a later stage in the sound change.
Influence of Hydraulic Hysteresis on the Shear Strength of Unsaturated Soils and Interfaces
Authors: Khoury Charbel N. , Miller Gerald A.
Published: October 2011

The soil water characteristic curve (SWCC) portrays the relationship between soil suction and water content. This curve represents a fundamental behavior of unsaturated soils, from which many engineering properties (e.g., hydraulic conductivity, shear strength) can be estimated. However, the SWCC exhibits hysteretic behavior where a soil with different values of moisture content (e.g., due to seasonal variations) corresponding to drying and wetting paths can have the same suction. Hysteretic behavior (hydraulic hysteresis) can significantly influence the mechanical response of soils and soil-structure interfaces. This paper describes an investigation of the influence of hydraulic hysteresis during drying and wetting on the shearing response of unsaturated silty cohesionless soil alone and in contact with a rough steel counterface using a specially designed direct shear apparatus. For both soil and rough interface conditions, it was found that shear strength following a drying-wetting path was higher than for only the drying path, at similar suction and net normal stress. The magnitude of the difference in shear strength appears to correlate reasonably well with the difference in volumetric water content between the drying-wetting and drying paths at a given suction and net normal stress prior to shearing.
A thrombophilia előfordulása és a veseerek thrombosisának veszélye veseátültetett betegeknél
Authors: Toronyi Éva , Máthé Zsolt , Chmel Rita , Varga Marina , Kozma Veronika , Trent Roland , Tőzsér Gellért , Nagy Gergely , Langer Róbert
Published: October 2011

Absztrakt

Bevezetés: A végstádiumú veseelégtelenség optimális kezelése a veseátültetés. A korai posztoperatív periódusban az arteria és a vena renalis thrombosisa a leggyakoribb éreredetű szövődmény, mely általában az átültetett vese elvesztéséhez vezet. Klinikánkon egy 28 éves férfi esetében a transzplantációt 8 órával követően vena renalis thrombosist diagnosztizáltunk. Azonnali reoperációval sikerült a venát recanalisálni és a graftot megmenteni. Ez az eset késztetett minket arra, hogy áttekintsük a thrombophilia és a vesetranszplantációt követő thromboticus szövődmények irodalmát. Módszer: A Pubmed 2010. december 31-ig terjedő adatbázisában tekintettük át a humánvonatkozású, angol nyelvű közleményeket. Részletesen 27 publikációt elemeztünk. Beszámolunk a hypercoagulabilis állapotok és a vesegraftthrombosis előfordulásának gyakoriságáról, a Leiden-mutáció és a prothrombin G20210A mutáció venás thromboemboliában való prediktív értékéről. Eredmények: Az irodalom alapján nem egyértelmű az összefüggés a thrombophilia és a veseerek thrombosisa között, nincs egységes állásfoglalás a transzplantációra váró betegek thrombophilia-szűrésének prediktív és költség-haszon értékére vonatkozóan. Összefoglalás: Saját kedvezőtlen tapasztalataink alapján javasoljuk a transzplantációs várólistára kerülő betegek thrombophilia-szűrését és a veszélyeztetett betegeknél thrombosisprofilaxis alkalmazása helyett terápiás adagú anticoagulans-kezelés beállítását a poszttranszplantációs időszakban. Gazdasági költség-haszon elemzések is azt támasztják alá, hogy a sikeres transzplantációval a szűrés költsége megtérül. 3 éves időszakot vizsgálva a dialíziskezelés költsége lényegesen magasabb, mint a transzplantációé.
Compact form of expressions for inductance calculation of meander inductors
Authors: Stojanovic Goran , Zivanov Ljiljana , Damjanovic Mirjana
Published: October 2011

The quality of modeling and analyzing of RF IC with planar inductors extremely depends on accuracy of expression for inductance. In this paper efficient methods for total inductance calculation of meander inductor are given. By using proposed algorithm, we are able to predict correctly all inductance variations introduced by varying geometry parameters. Our. developed program gives possibility for fast and accurate inductance calculation for meander inductor, while new expression in monomial form is useful for optimization of this inductor. The results validations, given by proposed software tool are conformed by comparison with measured data from literature.
Nikola Tesla’s contributions to radio developments
Authors: Marincic Aleksandar , Civric Zorica , Milovanovic Bratislav
Published: October 2011

nema
Wireless powering for low-power distributed sensors
Authors: Popovic Zoya
Published: October 2011

In this paper, an overview of the field of wireless powering is presented with an emphasis on low-power applications. Several rectenna elements and arrays are discussed in more detail: (1) a 10-GHz array for powering sensors in aircraft wings; (2) a single antenna in the 2.4-GHz ISM band for low-power assisted-living sensors; and (3) a broadband array for power harvesting in the 2-18GHz frequency range.
Power signal disturbance classification using wavelet based neural network
Authors: Suja S. , Jerome Jovitha
Published: October 2011

In this paper, the power signal disturbances are detected using discrete wavelet transform (DWT) and categorized using neural networks. This paper presents a prototype of power quality disturbance recognition system. The prototype contains three main components. First a simulator is used to generate power signal disturbances. The second component is a detector which uses the technique of DWT to detect the power signal disturbances. DWT is used to extract disturbance features in the power signal. These coefficients obtained from DWT are further subjected to statistical manipulations for increasing the detection accuracy. The third component is neural network architecture to classify the power signal disturbances with increased accuracy of detection.
Generalized two axes model of a squirrel-cage induction motor for rotor fault diagnosis
Authors: Samir Hamdani , Omar Touhami , Rachid Ibtiouen
Published: October 2011

A generalized two axes model of a squirrel-cage induction motor is developed This model is based on a winding function approach and the coupled magnetic circuit theory and takes into account the stator and the rotor asymmetries due to faults. This paper presents a computer simulation and experimental dynamic characteristics for a healthy induction machine, machine with one broken bar and a machine with two broken bars. The results illustrate good agreement between both simulated and experimental results. Also, the power spectral density PSD was performed to obtain a stator current spectrum.
Determination of characteristics of feromagnetic material using modern data acquisition system
Authors: Koprivica Branko , Milovanovic Alenka , Djekic Milic
Published: October 2011

This paper describes the use of modern measuring and data acquisition system for determining characteristics of feromagnetic material. For this purpose data acquisition card NI USB-6009, PC with data acquisition software and fluxmeter Electrical Steel Measuring System MPG 100 D were used. Based on the results obtained by measurements the modeling of hysteresis loop is performed by using appropriate mathematical model.
Improvement the DTC system for electric vehicles induction motors
Authors: Arif Ali , Betka Achour , Guettaf Abderezak
Published: October 2011

A three-phase squirrel-cage induction motor is used as a propulsion system of an electric vehicle (EV). Two different control methods have been designed. The first is based on the conventional DTC Scheme adapted for three level inverter. The second is based on the application of fuzzy logic controller to the DTC scheme. The motor is controlled at different operating conditions using a FLC based DTC technique. In the simulation the novel proposed technique reduces the torque and current ripples. The EV dynamics are taken into account.
Philosophy of Education as an Exercise in Thought: To Not Forget Oneself When ‘things Take Their Course’
Authors: Masschelein Jan , Todd Sharon
Published: October 2011

Starting from a distinction between a critical and an ascetic tradition in philosophy and taking into account their different stances towards the present, the article proposes a practice of philosophy of education within the ascetic tradition. In this tradition, the work of philosophy is in the first place a work on the self — that is, putting oneself to ‘the test of contemporary reality’ — implying an enlightenment not of others but of oneself; however, of oneself not as subject of knowledge, but as subject of action. Putting oneself to the test is, therefore, an exercise in the context of self-education. The article indicates how this exercise can be described as an exercise of/in thought, how it has to be conceived not as a private matter but as a public gesture and as a condition for a truth-telling that is in the first place illuminating and inviting. In order to do so, the article first recalls how Hannah Arendt describes her own work and how this indicates what kind of philosophical practice is entailed in the ascetic tradition. In line with this description, a topical example (i.e. the films of the Belgian Dardenne brothers) is offered of how educational philosophical research in this tradition is carried out today. And, finally, it is clarified how this relates to a proposal for doing ‘empirical’ philosophical research and for creating laboratories.

What is proposed is a meditation on the phrase ‘transformation of the educational system’, paying attention to the sense of the words, and showing what the desire for educational change can reveal. After explaining to what extent ‘educational system’ is a quasi-oxymoron, the meaning of ‘transformation’ has to be compared to those of revolution and utopia. The claim to be transforming the educational system is an attempt to adapt education to social and political situations and constraints. The case of the Langevin-Wallon project in France, which was never applied, helps when wondering what has to be adapted to what. What sort of reciprocity is there between school and society? The organisation of knowledge itself can be submitted to a transformation. Jeremy Bentham's Chrestomathia expresses such a conception through an unheeded and somehow utopian project. The desire for something new is in itself problematical, and the very fact of it being new cannot be an aim.
Role and Function of ‘Philosophy of Education’ within the Educational Sciences: A Cross-National Attempt
Authors: Kraft Volker , Conroy James C.
Published: October 2011

Disciplinary structures of education across Europe are rather different mainly due to the fact that education as an anthropological phenomenon is deeply rooted in specific cultural and national contexts. For this reason the role philosophy of education plays within the given national educational sciences is somewhat divergent and not easy to compare. In face of these difficulties the article argues for a cross-national attempt using theorems deriving from modern systems theory. From such a perspective philosophy of education can be regarded as a special ‘knowledge system’ and its function consists in re-including what has been excluded in the process of rationalisation of education; it serves, so to speak, as a special type of reflection knowledge which is as timeless as it is necessary and therefore of meta-national relevance and indispensable for the process of Europeanisation of education.

It is reasonably easy to accept Kraft's claim that education is indeed a local social practice, which has emerged out of complex historical and social forces. But to do so is not to accept that there is some kind of incommensurability between the conceptual languages that emerge out of such local conditions. Indeed underlying the particular understandings/problem/challenges that emerge in particular political and cultural contexts are deep commonalities and it is part of the task of philosophy of education to make sense of these. In distinction to Kraft's proposal that we disaggregate the theoretical and the practical, so as to free up the philosophical to do its proper work, the argument presented here is that such dissociation will fail to enable philosophy to do the work of moving education forward. It will fail because it leaves the teacher bereft of the necessary intellectual resources to engage professionally in the task of education. Education is ineluctably a normative engagement and as such requires the teacher to reflect philosophically on its nature.
The Projectisation, Marketisation and Therapisation of Education
Authors: Brunila Kristiina
Published: October 2011

Publicly funded projects with economic aims and discourses have permeated the public sector, including education. In practice this has meant a shift whereby publicly funded education has evolved into a series of business-oriented projects with individually targeted activities. The rapidly increasing amount of project-based work in education is a result of a shift whereby Finland has become a project society. In this article I will disclose the alliance between projectisation, marketisation and therapisation of education in Finland by analysing project-based equality training in education and project-based training and guidance for young adults. Both activities operate in quite different contexts in the field of adult education but are still targeted by similar forms of power that I aim to analyse in this article.
Association of Pretransplant Glycemic Control With Posttransplant Outcomes in Diabetic Kidney Transplant Recipients
Authors: Molnar Miklos Z. , Huang Edmund , Hoshino Junichi , Krishnan Mahesh , Nissenson Allen R. , Kovesdy Csaba P. , Kalantar-Zadeh Kamyar
Published: October 2011

OBJECTIVE

Observational studies have yielded inconsistent findings regarding the association of hemoglobin A1c (HbA1c) with survival in diabetic patients on dialysis. The association between pretransplant glycemic control and short- and long-term posttransplant outcomes in kidney transplant recipients is not clear.

RESEARCH DESIGN AND METHODS

Linking the 5-year patient data of a large dialysis organization (DaVita) to the Scientific Registry of Transplant Recipients, we identified 2,872 diabetic dialysis patients who underwent first kidney transplantation. Mortality or graft failure and delayed graft function (DGF) risks were estimated by Cox regression (hazard ratio [HR]) and logistic regression (odds ratio), respectively.

RESULTS

Patients were 53 ± 11 years old and included 36% women and 24% African Americans. In our fully adjusted model, allograft failure–censored, all-cause death HR and 95% CI for time-averaged pretransplant HbA1c categories of 7 to <8%, 8 to <9%, 9 to 10%, and ≥10%, compared with 6 to <7% (reference), were 0.89 (0.59–1.36), 2.06 (1.31–3.24), 1.41 (0.73–2.74), and 3.43 (1.56–7.56), respectively; and graft failure–censored cardiovascular death HR was 0.38 (0.13–1.05), 1.78 (0.69–4.55), 1.59 (0.44–5.76), and 4.28 (0.85–21.64), respectively. We did not find any difference in risk of death-censored graft failure or DGF with different pretransplant HbA1c levels.

CONCLUSIONS

Poor pretransplant glycemic control appears associated with decreased posttransplant survival in kidney transplant recipients, whereas allograft outcomes may not be affected.
A Novel Unstable Mutation in Mitochondrial DNA Responsible for Maternally Inherited Diabetes and Deafness
Authors: Bannwarth Sylvie , Abbassi Meriame , Valéro René , Fragaki Konstantina , Dubois Noémie , Vialettes Bernard , Paquis-Flucklinger Véronique
Published: October 2011

OBJECTIVE

The m.3243A>G mutation in mitochondrial DNA (mtDNA) is responsible for maternally inherited diabetes and deafness (MIDD). Other mtDNA mutations are extremely rare.

RESEARCH DESIGN AND METHODS

We studied a patient presenting with diabetes and deafness who does not carry the m.3243A>G mutation.

RESULTS

We identified a deficiency of respiratory chain complex I in the patient’s fibroblasts. mtDNA sequencing revealed a novel mutation that corresponds to an insertion of one or two cytosine residues in the coding region of the MT-ND6 gene (m.14535_14536insC or CC), leading to premature stop codons. This heteroplasmic mutation is unstable in the patient’s somatic tissues.

CONCLUSIONS

We describe for the first time an unstable mutation in a mitochondrial gene coding for a complex I subunit, which is responsible for the MIDD phenotype. This mutation is likely favored by the m.14530T>C polymorphism, which is homoplasmic and leads to the formation of an 8-bp polyC tract responsible for genetic instability.
Evaluation of catastrophic musculoskeletal injuries in Thoroughbreds and Quarter Horses at three Midwestern racetracks
Authors: Beisser Andrea L. , McClure Scott , Wang Chong , Soring Keith , Garrison Rudy , Peckham Bryce
Published: October 2011

Objective—To determine the incidence of and compare the types of catastrophic musculoskeletal injuries (CMIs) sustained in Thoroughbreds and Quarter Horses during racing at 3 Midwestern racetracks from 2000 to 2006.

Design—Retrospective cohort study.

Animals—139 Thoroughbred and 50 Quarter Horse racehorses euthanized because of CMIs.

Procedures—Veterinary officials from 3 Midwestern racing jurisdictions provided injury reports for Thoroughbreds and Quarter Horses that sustained CMIs (which required euthanasia) and the total number of race starts for each year. The number of CMIs/1,000 starts was determined for each racetrack. Past performance reports for each horse with a CMI were evaluated.

Results—The total number of race starts (both breeds) at the 3 racetracks from 2000 through 2006 was 129,460, with an overall incidence of 1.46 CMIs/1,000 race starts. Incidences of CMIs among racetracks were similar. Of horses that sustained a CMI, the median age of Thoroughbreds at first race was 3 years, compared with a median age of 2 years for Quarter Horses. A larger proportion of Thoroughbreds sustained a CMI in a claiming race than did Quarter Horses, and a larger proportion of Quarter Horses sustained a CMI in a futurity trial than did Thoroughbreds. The most common site for CMIs in Thoroughbreds was the left forelimb (69/124 [55.6%]), whereas most CMIs in Quarter Horses involved the right forelimb (18/30 [60.0%]).

Conclusions and Clinical Relevance—Differences identified between CMIs in Thoroughbred and Quarter Horse racehorses should allow veterinarians to focus on horses and anatomic regions of greatest risk of CMI during racing.
Structure and properties of solid solutions in the Mg-Al-B system
Authors: Sevastyanova Ludmila , Gulish Olga , Stupnikov Vladimir , Genchel Vladimir , Kravchenko Oleg , Bulychev Boris , Lunin Roman , Tarasov Valeriy
Published: October 2011

Compounds with the general formula Mg1−x
AlxB2 were obtained by two-step ceramic synthesis. All compounds were characterized by X-ray diffraction, NMR spectroscopy, and by four point probe resistivity measurements in various magnetic fields method. The diborides unit cell parameters were determined as a function of the Al mole fraction. With the vaues of x up to 0.40 (where x is the composition of the stock prepared for sintering), the unit cell parameters of Mg1−x
AlxB2 are similar to those of pure MgB2 and the superconducting transition temperature was lowered. For stock compositions of 0:25 ≤ x ≤ 0:60, the products contain a superstructure, also superconducting phase, which becomes the only product at x = 0:50, and at x > 0:60 this phase is replaced by AlB2-based solid solutions.
Design of miniaturization resonant cavities using metamaterial
Authors: Yu Guan , Cao Li , Zhou Man
Published: October 2011

Based on the method of transformation optics, we show the miniaturization of a resonant cavity filled with metamaterials. Because the electromagnetic behavior in the transformation space is invariant in the original space, the quality factor Q and the resonant modes of a miniaturized resonant cavity filled with metamaterial are the same as for those in the original space. Theoretical analysis and numerical simulation confirms that the miniaturization of resonant cavities is effective.
Geometric phase decomposition in the basis of Hermite-Gaussian functions
Authors: Aleksiejunas Rimvydas , Ivaska Vladislovas
Published: October 2011

The work presents geometric phase decomposition for analytical signals using Hermite-Gaussian functions. The decomposition is based on the time-frequency distribution with reassigned and multi-tapered spectrogram resulting in increased phase estimation resolution. Numerical analysis is applied to a number of SU(2) evolutions, such as spin-1/2 particle in a static and rotating magnetic field, as well as polarization rotation of a plane wave in optically active medium. Geometric phase decomposition results are provided also for quantum harmonic oscillator and a radiation field of an electric dipole exited by a short pulse.
Large deformation analysis of Euler-Bernoulli beamshell under own weight based on HAM
Authors: Sohouli Abdol , Kimiaeifar Amin , Mohsenzadeh Afshin , Mohebpour Saeed
Published: October 2011

Large deformation of a horizontally uniform cantilevered Euler-Bernoulli beamshell subjected to its own weight is studied. The governing equation for the first time is analytically solved using the analytical technique for nonlinear problems Homotopy Analysis Method (HAM). A series solution is presented that can be used for the analysis of beamshells undergoing large deformations with wide range of weight, material/cross section properties and lengths. The results obtained by HAM are compared with the results reported in the previous works, and good agreement is found. Finally, the load-displacement characteristics of a uniform cantilever beamshell under different load conditions, dimensionless weight parameter are presented.
Early development and progression of heterotopic ossification in cervical total disc replacement
Authors: Lee Soo Eon , Chung Chun Kee , Jahng Tae Ahn
Published: October 2011

Object

The purpose of cervical total disc replacement (TDR) is to decrease the incidence of adjacent segment disease through motion preservation. Heterotopic ossification (HO) is a well-known complication after hip and knee arthroplasties. There are few reports regarding HO in patients undergoing cervical TDR, however; and the occurrence of HO and its effects on cervical motion have rarely been reported. Moreover, temporal progression of HO has not been fully addressed. One goal of this study involved determining the incidence of HO following cervical TDR, as identified from plain radiographs, and demonstrating the progression of HO during the follow-up period. A second goal consisted of determining whether segmental motion could be preserved and identifying the relationship between HO and clinical outcomes.

Methods

The authors conducted a retrospective clinical and radiological study of 28 consecutive patients who underwent cervical TDR with Mobi-C prostheses (LDR Medical) between September 2006 and October 2008. Radiological outcomes were evaluated using lateral dynamic radiographs obtained preoperatively and at 1, 3, 6, 12, and 24 months postoperatively. The occurrence of HO was interpreted on lateral radiographs using the McAfee classification. Cervical range of motion (ROM) was also measured. The visual analog scale (VAS) and Neck Disability Index (NDI) were used to evaluate clinical outcome.

Results

The mean follow-up period was 21.6 ± 7.0 months, and the mean occurrence of HO was at 8.0 ± 6.6 months postoperatively. At the last follow-up, 18 (64.3%) of 28 patients had HO: Grade I, 6 patients; Grade II, 8 patients; Grade III, 3 patients; and Grade IV, 1 patient. Heterotopic ossification progression was proportional to the duration of follow-up; HO was present in 3 (10.7%) of 28 patients at 1 month; 7 (25.0%) of 28 patients at 3 months; 11 (42.3%) of 26 patients at 6 months; 15 (62.5%) of 24 patients at 12 months; and 17 (77.3%) of 22 patients at 24 months. Cervical ROM was preserved in Grades I and II HO but was restricted in Grades III and IV HO. Clinical improvement according to the VAS and NDI was not significantly correlated with the occurrence of HO.

Conclusions

The overall incidence of HO after cervical TDR was relatively high. Moreover, HO began unexpectedly to appear early after surgery. Heterotopic ossification progression was proportional to the time that had elapsed postoperatively. Grade III or IV HO can restrict the cervical ROM and may lead to spontaneous fusion; however, the occurrence of HO did not affect clinical outcome. The results of this study indicate that a high incidence of HO with the possibility of spontaneous fusion is to be expected during long-term follow-up and should be considered before performing cervical TDR.
Continuous preparation of carbon-nanotube-supported platinum catalysts in a flow reactor directly heated by electric current
Authors: Schlange Alicja , dos Santos Antonio Rodolfo , Kunz Ulrich , Turek Thomas
Published: October 2011

In this contribution we present for the first time a continuous process for the production of highly active Pt catalysts supported by carbon nanotubes by use of an electrically heated tubular reactor. The synthesized catalysts show a high degree of dispersion and narrow distributions of cluster sizes. In comparison to catalysts synthesized by the conventional oil-bath method a significantly higher electrocatalytic activity was reached, which can be attributed to the higher metal loading and smaller and more uniformly distributed Pt particles on the carbon support. Our approach introduces a simple, time-saving and cost-efficient method for fuel cell catalyst preparation in a flow reactor which could be used at a large scale.
Evaluation of two methods of preoperative hair removal and their relationship to postoperative wound infection
Authors: Adisa Adewale Oluseye , Lawal Olukayode O , Adejuyigbe Olusanya
Published: October 2011

Introduction: When a surgical operation is to be conducted through a hair bearing part of the body, hair removal is often performed. This study aimed to evaluate the relationship of two methods of preoperative hair removal to postoperative wound infection in a developing country where razor shaving is very popular. Methodology: Consecutive consenting patients scheduled to have such operations were randomized into two groups. One group had hair removal by shaving with a razor blade while the other had hair removed by depilatory cream. Adequacy of hair removal and presence of skin injuries and/or reactions were noted preoperatively. Details of the procedures were recorded and patients were then assessed for postoperative wound infection. Results: A total of 165 patients were studied. Of the 79 patients who had hair removal by depilatory cream, hair was completely removed in 70 (88.6%) compared to 53 (61.6%) of the 86 patients who had razor hair shaving (p < 0.0001). Skin injuries were noted in 24 (27.9%) of the razor group and 3 (3.8%) of patients who had depilatory cream, (p = 0.001). Thirteen patients (7.9%) had postoperative wound infection including 2 (2.5%) in the depilatory cream group and 11 (12.8%) of the razor group. A significant association was found between preoperative skin injuries and postoperative wound infections. Conclusion: Preoperative hair removal with razor shaving predisposes to skin injuries which in turn significantly influence postoperative wound infection rates. Such injuries and resultant wound infection are fewer when depilatory cream is used for hair removal.
Reconstructing the realized niche of phytoplankton species from environmental data: fitness versus abundance approach
Authors: Grüner Nico , Gebühr Christina , Boersma Maarten , Feudel Ulrike , Wiltshire Karen H. , Freund Jan A.
Published: October 2011

The classification of the ecological niche and the grouping of species into generalists and specialists are established ecological concepts. In this study, we compare two methods for the calculation of the realized ecological niche from long‐term species data. As the first method, we present a new approach to reconstruct the realized niche not in terms of abundance but via a measure of fitness (optimal niche), which we call the Optimal Niche Estimate (ONE). The second method, the outlying mean index (OMI) analysis, is performed with abundance data for calculating the ecological niche. We demonstrate and discuss differences between methods by applying them to time series of three phytoplankton species from the Helgoland Roads long‐term data set: Ceratium fusus, Odontella regia, and Paralia sulcata.
Possible catalytic effects of ice particles on the production of NOx by lightning discharges
Authors: Peterson H. S. , Beasley W. H.
Published: October 2011

Abstract. It is well known that lightning produces NOx as a result of the high temperatures in discharge channels. Since most viable proposed electrification mechanisms involve ice crystals, it is reasonable to assume that lightning discharge channels frequently pass through fields of ice particles of various kinds. We address the question of whether ice crystals may serve as catalysts for the production of NOx by lightning discharges. If so, and if the effect is large, it would need to be taken into account in estimates of global NOx production by lightning. In this theoretical study, we make a series of plausible assumptions about the temperature and concentration of reactant species in the environment of discharges and we postulate a mechanism by which ice crystals are able to adsorb nitrogen atoms. We then compare production rates between uncatalyzed and catalyzed reactions at 2000 K, 3000 K, and 4000 K, which are reasonable temperatures in lightning channels as they cool down. Ice crystal catalysis is expected to produce 2.7 times more NO than if ice crystals were not present. Catalyzed NO production rates are greater at 2000 K, whereas uncatalyzed production rates are greater at 4000 K. Thus, temperatures that favor rapid NO production without ice crystals adsorbing nitrogen atoms are unfavorable for NO production in the presence of ice crystals, and vice versa. The density of atmospheric ice crystals is much larger at 10 km where intracloud (IC) flashes peak than at 5 km where cloud to ground (CG) flashes peak, thus catalytic processes are expected to be more important for IC flashes than CG flashes, perhaps explaining a portion of the discrepancy in IC and CG production rates.
Multiple-sulfur isotope effects during photolysis of carbonyl sulfide
Authors: Lin Y. , Sim M. S. , Ono S.
Published: October 2011

Abstract. Laboratory experiments were carried out to determine sulfur isotope effects during ultraviolet photolysis of carbonyl sulfide (OCS) to carbon monoxide (CO) and elemental sulfur (S0). The OCS gas at 3.7 to 501 mbar was irradiated with or without a N2 bath gas using a 150 W Xe arc lamp. Sulfur isotope ratios for the product S0 and residual OCS were analyzed by an isotope ratio mass-spectrometer with SF6 as the analyte gas. The isotope fractionation after correction for the reservoir effects is −6.8‰ for the ratio 34S/32S, where product S0 is depleted in heavy isotopes. The magnitude of the overall isotope effect is not sensitive to the addition of N2 but increases to −9.5‰ when radiation of λ > 285 nm is used. The measured isotope effect reflects that of photolysis as well as the subsequent sulfur abstraction (from OCS) reaction. The magnitude of isotope effects for the abstraction reaction is estimated by transition state theory to be between −18.9 and −3.1‰ for 34S which gives the photolysis isotope effect as −10.5 to +5.3‰. The observed triple isotope coefficients are ln(δ34S + 1)/ln(δ34S + 1) = 0.534 ± 0.005 and ln(δ36S + 1)/ln(δ34S + 1) = 1.980 ± 0.021. These values differ from canonical values for mass-dependent fractionation of 0.515 and 1.90, respectively. The result demonstrates that the OCS photolysis does not produce large isotope effects of more than about 10‰ for 34S/32S, and can be the major source of background stratospheric sulfate aerosol (SSA) during volcanic quiescence.
Validation of TES methane with HIPPO aircraft observations: implications for inverse modeling of methane sources
Authors: Wecht K. J. , Jacob D. J. , Wofsy S. C. , Kort E. A. , Worden J. R. , Kulawik S. S. , Henze D. K. , Kopacz M. , Payne V. H.
Published: October 2011

Abstract. We validate satellite methane observations from the Tropospheric Emission Spectrometer (TES) with 151 aircraft vertical profiles over the Pacific from the HIAPER Pole-to-Pole Observation (HIPPO) program. We find that a collocation window of ±750 km and ±24 h does not introduce significant error in comparing TES and aircraft profiles. We validate both the TES standard product (V004) and an experimental product with two pieces of information in the vertical (V005). We determine a V004 mean bias of 65.7 ppb with residual standard deviation of 44.2 ppb. For V005 we determine mean biases (residual standard deviations) in the lower and upper troposphere of 18.2 (31.1) and 49.4 (33.2) ppb, respectively. TES errors show no significant dependence on latitude or surface type. Even when V005 cannot retrieve two pieces of information it still performs better than V004. An observation system simulation experiment (OSSE) with the GEOS-Chem chemical transport model (CTM) and its adjoint shows that TES V004 has only limited value for constraining methane sources. Our successful validation of V005 encourages its production as a standard retrieval to replace V004.
Properties of standing Kruskal-Schwarzschild-modes at the magnetopause
Authors: Plaschke F. , Glassmeier K.-H.
Published: October 2011

Abstract. The radial, oscillatory motion of the Earth's magnetopause has been found to occur predominantly with some distinct, sometimes called "magic" frequencies, which have been attributed to magnetospheric wave guide modes, typical solar wind variations or, more recently, surface waves on the magnetopause standing between the northern and southern ionospheres. In this paper we present for the first time a derivation of these surface waves, denominated as Kruskal-Schwarzschild-modes (KS-modes), in the approximation of the ideal, single-fluid magnetohydrodynamic theory for incompressible plasmas. The calculations are performed in the simplified geometry of the box magnetosphere with the magnetopause being a plane between two plasma regimes of homogeneous conditions. The reflection of the KS-modes at the ionospheres is being discussed. Under the given assumptions and realistic conditions the validity of the calculations is shown to be limited to cases of parallel or anti-parallel background magnetic fields on both sides of the magnetopause, respectively. For these cases a detailed discussion of the mode structure is presented. The magnetopause when affected by a KS-mode is found to resemble a membrane under tension with respect to its motion; the ionospheres act as supporting points of the membrane and the KS-modes correspond in this picture to their eigenmodes of oscillation. Localized pressure enhancements in the magnetosheath are discussed as possible excitation mechanism for the KS-modes.
Pliocene Ice Sheet Modelling Intercomparison Project (PLISMIP) – experimental design
Authors: Dolan A. M. , Koenig S. J. , Hill D. J. , Haywood A. M. , DeConto R. M.
Published: October 2011

Abstract. During the mid-Pliocene Warm Period (3.264 to 3.025 million yr ago), global mean temperature was similar to that predicted for the next century and atmospheric carbon dioxide concentrations were slightly higher. Sea level was also higher than today, implying a reduction in the extent of the ice sheets. Thus, the mid-Pliocene Warm Period provides a unique testing ground to investigate the stability of the Earth's ice sheets and their contribution to sea level in a warmer-than-modern world. Climate models and ice sheet models can be used to enhance our understanding of ice sheet stability, however, uncertainties associated with different ice-sheet modelling frameworks/approaches mean that a rigorous comparison of numerical ice sheet model simulations for the Pliocene is essential. As an extension to the Pliocene Model Intercomparison Project (PlioMIP; Haywood et al., 2010, 2011a), the Pliocene Ice Sheet Modelling Intercomparison Project (PLISMIP) will address these uncertainties. Here we outline the PLISMIP experimental design and initialisation conditions that have been adopted to simulate the Greenland and Antarctic ice sheets under present day and warm mid-Pliocene conditions. Not only will this project provide a new benchmark in the simulation of ice sheets in a past warm period, but the analysis of model sensitivity to various uncertainties could directly inform future predictions of ice sheet and sea level change.
Characterization of the hydrological functioning of the Niger basin using the ISBA-TRIP model
Authors: Pedinotti V. , Boone A. , Decharme B. , Crétaux J. F. , Mognard N. , Panthou G. , Papa F.
Published: October 2011

Abstract. During the 70s and 80s, West Africa has faced extreme climate variations with extended extreme drought conditions. Of particular importance is the Niger basin, since it traverses a large part of the Sahel and is thus a critical source of water in this semi arid region. However, the understanding of the hydrological processes over this basin is currently limited by the lack of spatially distributed surface water and discharge measurements. The purpose of this study is to use the ISBA-TRIP continental hydrologic system to explore key processes related to the hydrological cycle of the Niger Basin. The scheme accounts explicitly for the surface river routing, for the floodplains dynamic, and for the water storage using a deep aquifer reservoir. In the current study, simulations are done at a 0.5 by 0.5° spatial resolution over the 2002–2007 period using the atmospheric forcing provided by the AMMA Land surface Model Intercomparison Project (ALMIP). The model is intensively compared to in situ discharge measurements as well as satellite derived flood extent, total continental water storage changes and river height changes. The flooding scheme leads to a non-negligible increase of evaporation over large flooded areas, which decrease the Niger river flow by 15% to 50%, according to the observed station and the rainfall dataset used as forcing. This contributes to improve the simulation of the river discharges confirming for the need to incorporate flood representations into Land Surface Model. The model provides a good estimation of the surface water dynamics and accurately simulates the endorheic property of the Northern part of the basin. Moreover, the deep aquifer reservoir improves Niger low flows and the recession law during the dry season. This study also gives a basic estimation of aquifer recharge and of the total terrestrial water budget. The comparison with 3 satellite products from the Gravity Recovery and Climated Experiment (GRACE) is really optimistic and show a non negligible contribution of the deeper soil layers to the total storage (26% for groundwater and aquifer). Finally, sensitivity tests have shown that a good parameterization of routing models is required to optimize simulation errors. Indeed, the modification of some key parameters has non-negligible impacts on the model dynamics which gives perspectives for improving the model input parameters using future developments in remote sensing technologies such as the joint CNES-NASA satellite project SWOT (Surface Water Ocean Topography), which will provide water heights and extent at land surface with an unprecedented 50–100 m resolution and precision.