bluuebunny/crossref_metadata_2025_split huggingface dataset:
El Niño and prediction of anomalous monthly rainfalls in Ecuador
Authors: Rossel Frédéric , Cadier Eric 
Published: August 2009

AbstractThe coastal regions of Northern Peru and Southern Ecuador are well known for their sensitivity to the El Niño/Southern Oscillation (ENSO) phenomenon. Abundant rainfall is generally related to hot weather in the eastern tropical Pacific and to the weakened South Pacific trade winds, which allow the inter‐tropical convergence zone (ITCZ) to migrate far to the south and to convey warm moist air to the coastal area. A new monthly rainfall index series has been established using data from a network of 75 rainfall stations in Ecuador's coastal region. Throughout the analysis, a distinction is made between a ‘dependent’ data set (1964–1982) used as a training period and an ‘independent’ portion of the record (1983–1993) reserved for validation. Multiple regression models are developed to predict monthly rainfall in the Guayaquil area, using as predictors precipitation, sea surface temperature (SST), meridional and zonal wind in the eastern equatorial Pacific, with all predictions being based on a one‐month lead time. The resulting equations were used to predict rainfall anomalies in the independent data set. There is considerable predictive power for the rainy months of the year, the best predictability being for the period from March to May. The multiple linear correlations explain 60–82% of the monthly precipitation variance. The north region's pre‐season rainfall is the most powerful predictor for the rainy season peak in Guayaquil, whereas the eastern equatorial Pacific SST is the most powerful predictor for the end of the rainy season. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and evaluation of two fluorine‐18 labelled phenylbenzothiazoles as potential in vivo tracers for amyloid plaque imaging
Authors: Serdons K. , Vanderghinste D. , Van Eeckhoudt M. , Borghgraef P. , Kung H. , Van Leuven F. , de Groot T. , Bormans G. , Verbruggen A. 
Published: August 2009

AbstractUncharged derivatives of thioflavin‐T have known in vitro and in vivo affinity for amyloid β. We synthesized and evaluated two derivatives with a fluorine‐18 labelled fluoropropoxy substituent either at the 6‐position or at the 2′‐position of the 2‐(4′‐aminophenyl)‐1,3‐benzothiazole core with the aim to get suitable radiotracers to perform amyloid plaque imaging. The fluorine‐18 labelled compounds were obtained by nucleophilic substitution of the corresponding tosyl precursors with [18F]fluoride with a radiochemical yield of 50%, yielding 6‐(3′′‐[18F]fluoropropoxy)‐2‐(4′‐aminophenyl)‐1,3‐benzothiazole ([18F]2) and 2‐[2′‐(3′′‐[18F]fluoropropoxy)‐4′‐aminophenyl]‐1,3‐benzothiazole ([18F]3) with a specific activity between 33 and 51 GBq/µmol. The identity of the radiolabelled compounds was confirmed using radio‐LC‐MS and by comparing retention times on RP‐HPLC. Biodistribution studies in healthy mice showed for both compounds a relatively high initial brain uptake, which was significantly higher for [18F]2 than for [18F]3 (4.5% ID/g versus 3.0% ID/g, p<0.05). Wash‐out from control brain was faster for [18F]3. In vitro binding affinity tests using human AD brain homogenates revealed that only compound 2 has affinity for fibrillar amyloid β (Ki=14.5 nM). This was confirmed by the incubation of transgenic APP mouse brain sections with the cold compounds, where 3 did not stain any structure whereas 2 stained amyloid plaques present in APP mouse brain. These data suggest that [18F]2 may be a useful tracer for in vivo visualization of fibrillar amyloid β. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis of deuterium labelled diclofenac with improved isotopic enrichment
Authors: Wu Keying , Tian Lei , Li Hongye , Li Jian , Chen Liqin 
Published: August 2009

AbstractA five‐step synthesis of deuterium‐labelled diclofenac starting from 2‐phenyl[2H5] acetic acid is described. The synthesis prevents deuterium from scrambling during the reaction. It offers the labelled compound with over 99% isotopic enrichment. It also provides a possible alternative route for the synthesis of deuterium‐labelled 4′‐hydroxydiclofenac, which is the principal human metabolite of diclofenac. Copyright © 2009 John Wiley & Sons, Ltd.
Developing a sustainability ethic in leaders
Authors: Middlebrooks Anthony , Miltenberger Lauren , Tweedy James , Newman Grant , Follman Joanna 
Published: August 2009

AbstractThe triple bottom line of fiscal, social, and environmental success considerably alters how organizations (and stakeholders) measure sustainable success. More important, however, is the conceptual shift required to understand and successfully lead organizations within this increasingly accepted paradigm. This article uses a mixed‐methods approach to explore the conceptual development of a sustainability ethic in aspiring leaders. More specifically, the authors report research examining the curriculum and pedagogy of a leadership education effort, in this case a college‐level course, aimed at effecting change in both individual aspiring leaders and their immediate community. The article describes the philosophical and research base for the curriculum and specific activities with their pedagogical approach. Results show evidence of increased awareness, importance, and commitment to sustainability as well as changes in how students conceptualize sustainability leadership. Findings offer insights for further developing leadership education for sustainability.
LDR 2 LDR: University faculty communicating practice through theory
Authors: Waite Duncan 
Published: August 2009

AbstractAn act of leadership is always an act of practical theory. We lead because we hold visions of the world as it ought to be, because of the not yet, because of the potential that we see in ideas and people. Yet, there still exists a perceived binary between leadership theory (in the strong sense) and leadership practice, a binary that divides organizations, classrooms, and the differing bodies of leadership literature. In this Symposium, Duncan Waite and his colleagues discuss the barriers they have faced in bringing theory to the educational leadership classroom, as well as the promise they feel theory holds for more productive, equitable, and humane schooling organizations.
Collective leadership: Practice, theory, and praxis
Authors: Guajardo Miguel A. 
Published: August 2009

AbstractAn act of leadership is always an act of practical theory. We lead because we hold visions of the world as it ought to be, because of the not yet, because of the potential that we see in ideas and people. Yet, there still exists a perceived binary between leadership theory (in the strong sense) and leadership practice, a binary that divides organizations, classrooms, and the differing bodies of leadership literature. In this Symposium, Duncan Waite and his colleagues discuss the barriers they have faced in bringing theory to the educational leadership classroom, as well as the promise they feel theory holds for more productive, equitable, and humane schooling organizations.
Performing tip‐enhanced Raman spectroscopy in liquids
Authors: Schmid Thomas , Yeo Boon‐Siang , Leong Grace , Stadler Johannes , Zenobi Renato 
Published: August 2009

AbstractMany outstanding questions in biology and medicine require analytical tools that provide imaging and chemical information with high spatial resolution. Tip‐enhanced Raman spectroscopy (TERS) has been shown to allow both topographic and label‐free chemical information to be obtained with a lateral resolution of approximately 20–50 nm, but has been performed only in air or ultrahigh vacuum until now. Since most biological samples such as cells and tissues can only be studied in their active state if they are kept in aqueous buffers, TERS in liquids would be a crucial step towards nanoscale chemical analysis of living biological entities. For the first time, we introduce TERS experiments that have been performed with both the tip and sample completely immersed in water. We demonstrate that SiOx/Ag‐coated AFM tips provide enhancement factors of >104 with visible light irradiation and are robust enough to be used in water. Furthermore, the tips have been protected from contaminants by adsorbing a self‐assembled monolayer (SAM) of ethanethiolate on their Ag surfaces. The protection layer caused the enhancement to drop by a factor of approximately 5, but successfully prevented the adsorption of analyte molecules, carbon, and other contamination to the tip. Furthermore, our experiments have shown that the formation of carbonaceous contamination by laser irradiation on the tip is dramatically slowed down when TERS experiments are performed in water. Finally, a proof‐of‐principle study on SAMs of thiophenolate on Au surfaces demonstrates the feasibility of performing TERS in liquids. Copyright © 2009 John Wiley & Sons, Ltd.
Kinetic study of hydroperoxide epoxidation of 1‐octene in the presence of molybdenum disilicide as a catalyst in a low concentration range of olefin
Authors: Trach Yuriy B. , Makota Oksana I. 
Published: August 2009

AbstractThe kinetic regularities of the influence of low 1‐octene concentrations on its epoxidation by tert‐butyl hydroperoxide in the presence of molybdenum disilicide (MoSi2) as a catalyst were investigated. The minimum in the dependence of the initial rate of hydroperoxide consumption on 1‐octene concentration was observed. The kinetic scheme of epoxidation, which includes the competition between hydroperoxide and olefin for the catalytic active centers, was proposed. The equation for the reaction rate was derived according to the kinetic scheme. The kinetic parameters of epoxidation were calculated. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 623–628, 2009
Selective Fluorescence Quenching by Group 8 Metal Ions of a Water‐Soluble Poly(p‐phenylene vinylene) Derivative Bearing Oligo(oxyethylene) Pendants
Authors: Kim Kyu‐Nam , Kwon Young‐Wan , Choi Dong Hoon , Jin Jung‐Il 
Published: August 2009

AbstractA new fluorescing, water‐soluble derivative of poly(p‐phenylene vinylene), poly[2,5‐bis(oligooxyethylene)‐1,4‐phenylene vinylene], P(OE‐PV), is synthesized via a multistep route. The UV‐vis absorption and photoluminescence properties of the polymer are studied in aqueous solutions in the presence of 25 different metal ions. Among the ions studied, Fe(III), Os(III) and Ru(III) are found to effectively quench the fluorescence of P(OE‐PV). The Ru(III) is the most efficient in the fluorescence quenching. This observation implies that the polymer is a sensitive and selective chemosensor for these ions. It is suggested that the photoinduced electron transfer from the excited state of P(OE‐PV) to the metal ions may be the quenching mechanism application to the present systems.magnified image
Novel Thermosets from the Cationic Copolymerization of Modified Linseed Oils and Dicyclopentadiene
Authors: Xia Ying , Henna Phillip H. , Larock Richard C. 
Published: August 2009

AbstractA series of soft to tough copolymers have been prepared by the cationic copolymerization of the modified linseed oils Dilulin or ML189 with DCPD. Soxhlet extraction and solid‐state 13C NMR spectra indicate that the bulk copolymers consist of a cross‐linked oil/DCPD network interpenetrated with certain amounts of soluble components. The Tgs of the resulting Dil/DCPD and ML189/DCPD copolymers are in the range 15–83 and 8–77 °C, respectively, and increase linearly with the increase of the DCPD amount. The room‐temperature storage moduli range from 4.43 × 106 to 1.52 × 109 Pa for the Dil/DCPD copolymers and from 3.72 × 106 to 1.44 × 109 Pa for the ML189/DCPD copolymers.magnified image
LRRK2 R1628P variant is a risk factor of Parkinson's disease among Han‐Chinese from mainland China
Authors: Zhang Zijuan , Burgunder Jean‐Marc , An Xingkai , Wu Yan , Chen Wenjun , Zhang Jinhong , Wang Yingcheng , Xu Yanming , Gou Yingru , Yuan Guanggu , Mao Xueye , Peng Rong 
Published: August 2009

AbstractMutations in LRRK2, the gene that encodes leucine‐rich repeat kinase 2 (LRRK2), are associated with autosomal dominant and sporadic forms of Parkinson's disease (PD) and are the most common genetic causes of PD. Recently, a R1628P variant has been reported as a risk factor for PD in Taiwan and Singapore. To determine the association of this variant and PD in the Han‐Chinese population from mainland China, we analyzed its frequency in a cohort of 600 patients and 459 unrelated healthy controls. Forty (6.7%) patients were heterozygous and 3 (0.5%) homozygous for the R1628P variant, which was significantly more frequent than in the controls [2.4% heterozygous and 0.0% homozygous, Odds ratio = 3.14, 95%CI: 1.60–6.17, P < 0.01]. Considering the age at onset, this difference was found only in late‐onset PD (older than 50) [Odds ratio = 3.76, 95% CI: 1.90–7.45, P < 0.01]. Our data confirms that the LRRK2 R1628P variant is associated with an increased risk to develop late onset PD in the ethnic Han‐Chinese population. © 2009 Movement Disorder Society
Physical assessment as a predictor of mortality in people with Parkinson's disease: A study over 7 years
Authors: Gray William K. , Hildreth Anthony , Bilclough Julie A. , Wood Brian H. , Baker Katherine , Walker Richard W. 
Published: August 2009

AbstractThe primary aim of this study was to ascertain whether a battery of physical function measures in a Parkinson's disease (PD) patient cohort predicted mortality status at 7‐year follow‐up. Secondary aims were establishing which specific tests were the most useful, and whether PD phenotype was a predictor. A retrospective correlation design was used in this study. A cohort of 109 PD patients underwent baseline physiotherapy assessment of gait, balance, posture, muscle strength, and ability to change postural set. We compared mortality status at 7‐year follow‐up and baseline physical assessment tests. Tinetti gait and balance scores, UPDRS score, 10‐m walk test (time, velocity, and number of strides), posture in standing, lying to sitting, sitting to standing, getting up from floor assessments, and time to ascend and descend four steps were found to be statistically significant physical predictors of mortality at 7‐year follow‐up. In addition, age, sex, and mini‐mental state examination were significant nonphysical predictors of mortality. Using Cox regression, a survival model was constructed with age, sex, and Tinetti gait score as independent predictors of mortality. The results of this study suggest that there is a link between reduced physical function and an increased mortality risk in PD populations. © 2009 Movement Disorders Society
Restless legs syndrome, rapid eye movement sleep behavior disorder, and hypersomnia in patients with two parkin mutations
Authors: Limousin Nadège , Konofal Eric , Karroum Elias , Lohmann Ebba , Theodorou Ioannis , Dürr Alexandra , Arnulf Isabelle 
Published: August 2009

AbstractParkin gene mutations cause a juvenile parkinsonism. Patients with these mutations may commonly exhibit REM sleep behaviour disorders, but other sleep problems (insomnia, sleepiness, restless legs syndrome) have not been studied. The aim of this study was to evaluate the sleep‐wake phenotype in patients with two parkin mutations, compared with patients with idiopathic Parkinson's disease (iPD). Sleep interview and overnight video‐polysomnography, followed by multiple sleep latency tests, were assessed in 11 consecutive patients with two parkin mutations (aged 35–60 years, from seven families) and 11 sex‐matched patients with iPD (aged 51–65 years). Sleep complaints in the parkin group included insomnia (73% patients versus 45% in the iPD group), restless legs syndrome (45%, versus none in the iPD group, P = 0.04), and daytime sleepiness (45%, versus 54% in the iPD group). Of the parkin patients, 45% had REM sleep without atonia, but only 9% had a definite REM sleep behavior disorder. All sleep measures were similar in the parkin and iPD groups. Two parkin siblings had a central hypersomnia, characterized by mean daytime sleep latencies of 3 min, no sleep onset REM periods, and normal nighttime sleep. Although the patients with two parkin mutations were young, their sleep phenotype paralleled the clinical and polygraphic sleep recording abnormalities reported in iPD, except that restless legs syndrome was more prevalent and secondary narcolepsy was absent. © 2007 Movement Disorder Society
Launching invasive, first‐in‐human trials against Parkinson's disease: Ethical considerations
Authors: Kimmelman Jonathan , London Alex John , Ravina Bernard , Ramsay Tim , Bernstein Mark , Fine Alan , Stahnisch Frank W. , Emborg Marina Elena 
Published: August 2009

AbstractThe decision to initiate invasive, first‐in‐human trials involving Parkinson's disease presents a vexing ethical challenge. Such studies present significant surgical risks, and high degrees of uncertainty about intervention risks and biological effects. We argue that maintaining a favorable risk‐benefit balance in such circumstances requires a higher than usual degree of confidence that protocols will lead to significant direct and/or social benefits. One critical way of promoting such confidence is through the application of stringent evidentiary standards for preclinical studies. We close with a series of recommendations for strengthening the internal and external validity of preclinical studies, reducing their tendency toward optimism and publication biases, and improving the knowledge base used to design and evaluate preclinical studies. © 2009 Movement Disorder Society
On a generalized Appell system and monogenic power series
Authors: Bock S. , Gürlebeck K. 
Published: August 2009

AbstractRecently Appell systems of monogenic polynomials in ℝ3were constructed by several authors. Main purpose of this paper is the description of another Appell system that is complete in the space of square integrable quaternion‐valued functions. A new Taylor‐type series expansion based on the Appell polynomials is presented, which can be related to the corresponding Fourier series analogously as in the complex one‐dimensional case. These results find applications in the description of the hypercomplex derivative, the monogenic primitive of a monogenic function and the characterization of functions from the monogenic Dirichlet space. Copyright © 2009 John Wiley & Sons, Ltd.
Interface crack problems for metallic–piezoelectric composite structures
Authors: Natroshvili D. , Stratis I. G. , Zazashvili S. 
Published: August 2009

AbstractWe investigate three‐dimensional interface crack problems (ICP) for metallic–piezoelectric composite bodies. We give a mathematical formulation of the physical problem when the metallic and piezoelectric bodies are bonded along some proper part of their boundaries where an interface crack occurs. By potential methods the ICP is reduced to an equivalent strongly elliptic system of pseudodifferential equations on manifolds with boundary. We study the solvability of this system in different function spaces and prove uniqueness and existence theorems for the original ICP. We analyse the regularity properties of the corresponding electric and mechanical fields near the crack edges and near the curves where the boundary conditions change. In particular, we characterize the stress singularity exponents and show that they can be explicitly calculated with the help of the principal homogeneous symbol matrices of the corresponding pseudodifferential operators. We present some numerical calculations that demonstrate that the stress singularity exponents essentially depend on the material parameters. Copyright © 2009 John Wiley & Sons, Ltd.
Myocardial perfusion MRI with sliding‐window conjugate‐gradient HYPR
Authors: Ge Lan , Kino Aya , Griswold Mark , Mistretta Charles , Carr James C. , Li Debiao 
Published: August 2009

AbstractFirst‐pass perfusion MRI is a promising technique for detecting ischemic heart disease. However, the diagnostic value of the method is limited by the low spatial coverage, resolution, signal‐to‐noise ratio (SNR), and cardiac motion‐related image artifacts. In this study we investigated the feasibility of using a method that combines sliding window and CG‐HYPR methods (SW‐CG‐HYPR) to reduce the acquisition window for each slice while maintaining the temporal resolution of one frame per heartbeat in myocardial perfusion MRI. This method allows an increased number of slices, reduced motion artifacts, and preserves the relatively high SNR and spatial resolution of the “composite images.” Results from eight volunteers demonstrate the feasibility of SW‐CG‐HYPR for accelerated myocardial perfusion imaging with accurate signal intensity changes of left ventricle blood pool and myocardium. Using this method the acquisition time per cardiac cycle was reduced by a factor of 4 and the number of slices was increased from 3 to 8 as compared to the conventional technique. The SNR of the myocardium at peak enhancement with SW‐CG‐HYPR (13.83 ± 2.60) was significantly higher (P < 0.05) than the conventional turbo‐FLASH protocol (8.40 ± 1.62). Also, the spatial resolution of the myocardial perfection images was significantly improved. SW‐CG‐HYPR is a promising technique for myocardial perfusion MRI. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Theory of Q‐ball imaging redux: Implications for fiber tracking
Authors: Barnett Alan 
Published: August 2009

AbstractQ‐ball imaging is widely used to determine fiber directions for fiber tracking. In q‐ball imaging the directional dependence of water diffusion in tissue is described by Tuch's orientation distribution function (ODF); a different function, the q‐ball orientation distribution function, is measured using high angular resolution magnetic resonance diffusion imaging (HARDI). Tuch's ODF is assumed to be well approximated by the q‐ball ODF. In this study it is shown that: 1) the q‐ball ODF is not a good approximation to Tuch's ODF; 2) the properties of the q‐ball ODF depend strongly on q, the area of the diffusion sensitization gradients; and 3) the q‐ball ODF for a composite system is the weighted average of the q‐ball ODFs for each subsystem, but the weighting factor is the product of the percent composition and a renormalization factor. In addition, a derivation is presented of the q‐ball ODF for a system described by a Gaussian distribution and expressions are derived for both the dependence of the angular resolution on q and for the relation between the angular resolution and the signal loss. These findings might be useful in the design and interpretation of fiber‐tracking experiments. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Partial volume effect (PVE) on the arterial input function (AIF) in T1‐weighted perfusion imaging and limitations of the multiplicative rescaling approach
Authors: Hansen Adam E. , Pedersen Henrik , Rostrup Egill , Larsson Henrik B.W. 
Published: August 2009

AbstractThe partial volume effect (PVE) on the arterial input function (AIF) remains a major obstacle to absolute quantification of cerebral blood flow (CBF) using MRI. This study evaluates the validity and performance of a commonly used multiplicative rescaling of the AIF to correct for the PVE. In a group of six patients, perfusion imaging was performed using a T1‐weighted approach that minimizes confounding susceptibility artifacts. Various degrees of PVE were induced on the AIF and subsequently corrected using four different schemes of multiplicative AIF rescaling. Our results show that a multiplicative rescaling is not always applicable and can introduce a CBF bias. An easily measurable quantity denoted the tissue signal fraction (TSF) is proposed as a measure of the applicability of a multiplicative rescaling. For the present CBF quantification method, a TSF of <0.4 results in a CBF bias <15% after AIF rescaling. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.