bluuebunny/crossref_metadata_2025_split huggingface dataset:
The global footprint of persistent extra‐tropical drought in the instrumental era
Authors: Herweijer Celine , Seager Richard 
Published: January 2008

AbstractThe major North American droughts as per instrumental records are shown to be part of a larger, global pattern of low‐frequency drought variability. Drought in western North America during the 1850s–1860s, 1870s, 1890s, 1930s and 1950s, is shown to coincide with the occurrence of prolonged dry spells in parts of Europe, southern South America and western Australia. Tropical land regions are mostly wet during these periods, with the exception of central east Africa, southern India and Sri Lanka, which are dry. The recent 1998–2003 period of drought in western North America reveals a similar global hydroclimatic ‘footprint’ with the exception of a wet southern South America and continued dry conditions in the Sahel. Common to each of the six droughts is the persistence of anomalously cool east central tropical Pacific sea surface temperatures (SSTs). For the 1998–2003 case, the warming of SSTs everywhere outside of the east central tropical Pacific may be influencing precipitation and masking the influence of persistent precipitation anomalies driven from the tropical Pacific alone. In general, examination of these major historical extra‐tropical droughts reveals a hemispherically and, in the extra‐tropics, a zonally symmetric pattern consistent with forcing from the Tropics.Ensembles of model simulations forced by observed SSTs globally (Global Ocean Global Atmosphere, GOGA) and only within the tropical Pacific (Pacific Ocean Global Atmosphere‐Mixed Layer, POGA‐ML) are both able to capture the global pattern of the persistent extra‐tropical drought regimes since the mid‐nineteenth century. This implies that the recently demonstrated link between SST forcing and drought in North America is in fact only one part of a global hydroclimatic response to the persistence of cool SST anomalies in the tropical Pacific. Indian Ocean SST forcing is required to capture the droughts in central east Africa. Over Europe, the modelled, low‐frequency precipitation signal is unrealistically ENSO dominated, as the model does not faithfully reproduce the observed history of low‐frequency NAO variability. Overall, our results suggest that the global pattern of persistent drought appears to be a low‐frequency version of interannual ENSO‐forced variability. Copyright © 2008 Royal Meteorological Society
Weather patterns in eastern Slovakia 1717–1730, based on records from the Breslau meteorological network
Authors: Brázdil Rudolf , Kiss Andrea , Luterbacher Jürg , Valášek Hubert 
Published: January 2008

AbstractThe Breslau (Wrocław) physician, Johann Kanold established a network that included direct meteorological measurements and visual weather observations from several places in Europe. The results of the observations were published every quarter of a year for the 1717–1730 period. They included the first meteorological measurements from the Prešov station (1717–1720), made by the physician, Johann Adam Reimann for the recently defined eastern Slovakia (former Upper Hungary), as well as visual weather observations provided up to 1730 in a similar fashion in Kežmarok by George Buchholtz. The quality of the instrumental measurements of pressure and temperature is discussed. Observations from both places have been used to derive weighted temperature and precipitation indices. Three outstanding weather periods have been analysed in detail: a drought spring‐autumn in 1718, disastrous floods in 1725 and a severe and snowy winter in 1725–1726. The article is a contribution to the historical climatology of Slovakia and central Europe. Copyright © 2008 Royal Meteorological Society
Association between bruxism and nocturnal groaning
Authors: Manconi Mauro , Zucconi Marco , Carrot Benjamin , Ferri Raffaele , Oldani Alessandro , Ferini‐Strambi Luigi 
Published: January 2008

AbstractBruxism is a well‐known sleep‐related movement disorder, usually associated with teeth damage and morning temporo‐mandibular discomfort. Nocturnal groaning (NG) is a less common entity consisting of a nocturnal monotonous sound, which occurs during the expiratory phase, especially during REM sleep, recently classified among parasomnias. We describe the first case of an association between bruxism and NG. According to the polysomnographic findings, bruxism and NG episodes were closely related to each other and seemed to be organized in stereotyped sequences. Both phenomena always occurred during NREM sleep and were synchronous with cortical arousals, leg movements, and sympathetic activations. The hypothesis of a common trigger mechanism for NG and bruxism, through an arousal‐induced activation, is discussed. © 2007 Movement Disorder Society
Placebo response in Parkinson's disease: Comparisons among 11 trials covering medical and surgical interventions
Authors: Goetz Christopher G. , Wuu Joanne , McDermott Michael P. , Adler Charles H. , Fahn Stanley , Freed Curt R. , Hauser Robert A. , Olanow Warren C. , Shoulson Ira , Tandon P.K. ,   Parkinson Study Group, Leurgans Sue 
Published: January 2008

AbstractPlacebo‐associated improvements have been previously documented in small series of Parkinson's disease (PD) patients. Using a strict definition of placebo‐associated improvement, we examined rates and timing of placebo responses to identify patient‐ and study‐based characteristics, predicting positive placebo response in several PD clinical trials. We collected individual patient data from the placebo groups of 11 medical and surgical treatment trials involving PD patients with differing PD severities and placebo‐assignment likelihoods. We defined a positive placebo response as ≥50% improvement in total Unified Parkinson's Disease Rating Scale motor (UPDRSm) score or a decrease by ≥2 points on at least two UPDRSm items compared to baseline. We calculated positive placebo response rates at early (3–7 weeks), mid (8–18 weeks), and late (23–35 weeks) stages of follow‐up. Odds ratios for patient‐ and study‐based characteristics were obtained from a model fitted using generalized estimating equations. There were 858 patients on placebo who met inclusion criteria for analysis. Three studies involved patients without need of symptomatic treatment, two involved patients without motor fluctuations needing symptomatic treatment, and six (three medical and three surgical) involved patients with motor fluctuations. The overall placebo response rate was 16% (range: 0–55%). Patients with higher baseline UPDRSm scores and studies that focused on PD with motor fluctuations, surgical interventions, or those with a higher probability of placebo assignment showed increased odds of positive placebo response. Placebo responses were temporally distributed similarly during early, mid, and late phases of follow‐up. Placebo‐related improvements occur in most PD clinical trials and are similarly distributed across all 6 months of follow‐up. Recognition of factors that impact placebo response rates should be incorporated into individual study designs for PD clinical trials. © 2008 Movement Disorder Society
Are parkin patients particularly suited for deep‐brain stimulation?
Authors: Lohmann Ebba , Welter Marie‐Laure , Fraix Valérie , Krack Paul , Lesage Suzanne , Laine Sophie , Tanguy Marie‐Laure , Houeto Jean‐Luc , Mesnage Valérie , Pollak Pierre , Alexandra Durr  , Agid Yves , Brice Alexis ,   French Parkinson's Disease Genetics study group
Published: January 2008

AbstractPatients with parkin mutations are known to have slower PD progression and a better response to levodopa at lower doses than patients with idiopathic Parkinson's disease. To determine the effects of deep brain stimulation (DBS) on such patients, we have compared the follow‐up after surgery of 7 patients with one parkin mutation, 7 patients with two parkin mutations, and 39 patients without parkin mutations. Twelve to 24 months after neurosurgery, the daily doses of levodopa equivalent were significantly lower in patients with two parkin mutations, indicating that these patients benefit from DBS, and they might have more durable results. © 2008 Movement Disorder Society
Numerical field evaluation of healthcare workers when bending towards high‐field MRI magnets
Authors: Wang H. , Trakic A. , Liu F. , Crozier S. 
Published: January 2008

AbstractIn MRI, healthcare workers may be exposed to strong static and dynamic magnetic fields outside of the imager. Body motion through the strong, non‐uniform static magnetic field generated by the main superconducting magnet and exposure to gradient‐pulsed magnetic fields can result in the induction of electric fields and current densities in the tissue. The interaction of these fields and occupational workers has attracted an increasing awareness. To protect occupational workers from overexposure, the member states of the European Union are required to incorporate the Physical Agents Directive (PAD) 2004/40/EC into their legislation. This study presents numerical evaluations of electric fields and current densities in anatomically equivalent male and female human models (healthcare workers) as they lean towards the bores of three superconducting magnet models (1.5, 4, and 7 T) and x‐, y‐, and z‐ gradient coils. The combined effect of the 1.5 T superconducting magnet and the three gradient coils on the body models is compared with the contributions of the magnet and gradient coils in separation. The simulation results indicate that it is possible to induce field quantities of physiological significance, especially when the MRI operator is bending close towards the main magnet and all three gradient coils are switched simultaneously. Magn Reson Med 59:410–422, 2008. © 2008 Wiley‐Liss, Inc.
Functional assessment of the kidney from magnetic resonance and computed tomography renography: Impulse retention approach to a multicompartment model
Authors: Zhang Jeff L. , Rusinek Henry , Bokacheva Louisa , Lerman Lilach O. , Chen Qun , Prince Chekema , Oesingmann Niels , Song Ting , Lee Vivian S. 
Published: January 2008

AbstractA three‐compartment model is proposed for analyzing magnetic resonance renography (MRR) and computed tomography renography (CTR) data to derive clinically useful parameters such as glomerular filtration rate (GFR) and renal plasma flow (RPF). The model fits the convolution of the measured input and the predefined impulse retention functions to the measured tissue curves. A MRR study of 10 patients showed that relative root mean square errors by the model were significantly lower than errors for a previously reported three‐compartmental model (11.6% ± 4.9 vs 15.5% ± 4.1; P < 0.001). GFR estimates correlated well with reference values by 99mTc‐DTPA scintigraphy (correlation coefficient r = 0.82), and for RPF, r = 0.80. Parameter‐sensitivity analysis and Monte Carlo simulation indicated that model parameters could be reliably identified. When the model was applied to CTR in five pigs, expected increases in RPF and GFR due to acetylcholine were detected with greater consistency than with the previous model. These results support the reliability and validity of the new model in computing GFR, RPF, and renal mean transit times from MR and CT data. Magn Reson Med 59:278–288, 2008. © 2008 Wiley‐Liss, Inc.
Editing through multiple bonds: Threonine detection
Authors: Marjanska Malgorzata , Henry Pierre‐Gilles , Uğurbil Kâmil , Gruetter Rolf 
Published: January 2008

AbstractIn in vivo 1H spectroscopy, the signal at 1.32 ppm is usually assigned to lactate. This resonance position is shared with threonine at physiological pH. The similarity of spectral patterns of lactate and threonine renders the separate measurement of either threonine or lactate without and even with editing technically challenging. In this study, the threonine signal was detected using a single‐shot multiple‐bond editing technique and quantified in vivo in both rat and human brains. A threonine concentration was estimated at 0.8 ± 0.3 mM (mean ± SD, n = 6) in the rat brain and at ∼0.33 mM in the human brain. Magn Reson Med 59:245–251, 2008. © 2008 Wiley‐Liss, Inc.
Underestimation of roughness in rough rock joints
Authors: Hong Eun‐Soo , Lee Jong‐Sub , Lee In‐Mo 
Published: January 2008

AbstractNumerous studies have been made to improve Barton's shear strength model for the quantification of rock joints. However, in these previous studies, the roughness and shear strength of the rock joint have been underestimated especially for relatively high undulated profiles (joint roughness coefficient (JRC) >14). The main factors of roughness underestimation in rough rock joints are investigated for the proper quantification of rock joint roughness. The aliasing effect and the roughness characteristics are analyzed by using artificial joint profiles and natural rock joint profiles. A 3D camera scanner is adopted to verify the main source of underestimation when using conventional measurement methods. Shear strength tests are carried out by using two types of shear apparatus to study the roughness mobilization characteristics, which may also affect the roughness underestimation. The results of joint roughness assessment, such as aliasing and undulation of waviness, show that the roughness can be underestimated in relatively rough joint profiles (JRC>14). At least two components of roughness parameters are needed to properly represent the joint roughness, for example, the amplitude and the inclination angle of joint asperity. Roughness mobilization is affected by both the normal stress and the asperity scale. Copyright © 2008 John Wiley & Sons, Ltd.
Implicit integration of a chemo‐plastic constitutive model for partially saturated soils
Authors: Zhang H. W. , Zhou L. 
Published: January 2008

AbstractA chemo‐plastic constitutive model for partially saturated soils is proposed in this paper based on the existing models developed in Hueckel (Int. J. Numer. Anal. Meth. Geomech. 1997; 21:43–72) and Gallipoli et al. (Geotechnique 2003; 53:123–135). The chemical softening effects due to the increase in contaminant mass concentration are considered based on Hueckel's chemo‐plastic model. Gallipoli's model is used to simulate the effects of suction and degree of saturation on mechanical behavior of partially saturated porous materials. In order to implement the proposed model in a finite element code, a fully implicit backward‐Euler integration algorithm is put forward. Numerical solutions for the tests at local level and the application of the algorithm to the real boundary value problem demonstrate the accuracy and convergence properties of the proposed integration scheme. Copyright © 2008 John Wiley & Sons, Ltd.
The relationship of nursing staff to the hospitalization of nursing home residents
Authors: Decker Frederic H. 
Published: January 2008

AbstractResearchers have found registered nurse (RN) staffing unrelated to the prevention of hospitalizations of nursing home residents. Although most nursing home admissions are from hospitals, their studies involved residents who probably were not admitted from hospitals. In this study I examined data on 6,623 discharges of nursing home residents admitted or not admitted from a hospital. For patients with longer stays (>30 days), higher RN staffing levels in nursing homes reduced hospitalizations only for residents admitted from hospitals. Higher RN levels reduced hospitalizations more than higher licensed nurse levels or skill mix. Only among longer‐stay residents not admitted from hospitals was RN staffing unrelated to hospitalizations. Researchers may have found RN staffing unrelated to hospitalizations because samples were primarily longer‐stay residents not admitted from hospitals. Published 2008 Wiley Periodicals, Inc. Res Nurs Health 31:238–251, 2008
Patients' and health care practitioners' attributions about adherence problems as predictors of medication adherence
Authors: Cook Paul F. 
Published: January 2008

AbstractPatients and healthcare practitioners (HCPs) each have theories about the causes of medication adherence problems. Traditional patient education focuses on correcting patients' inaccurate beliefs, but more recent models suggest working within patients' theories. Secondary data from a telehealth medication adherence program were analyzed to determine whether patients' or HCPs' causal theories better predicted adherence, and the effect of discrepancy between HCP and patient theories. Patients with osteoporosis (N = 402) or endometriosis (N = 2,015) received telephone counseling. Adherence levels and patients' and HCPs' causal attributions were recorded at each call. Hierarchical linear modeling showed associations between patients' attributions and current‐session adherence, but HCP‐patient attribution discrepancies predicted better subsequent adherence in three of six empirical tests performed. © 2008 Wiley Periodicals, Inc. Res Nurs Health 31:261–273, 2008
Proton conducting membranes based on poly(vinyl chloride) graft copolymer electrolytes
Authors: Choi Jin Kyu , Kim Yong Woo , Koh Joo Hwan , Kim Jong Hak 
Published: January 2008

AbstractThe direct preparation of proton conducting poly(vinyl chloride) (PVC) graft copolymer electrolyte membranes using atom transfer radical polymerization (ATRP) is demonstrated. Here, direct initiation of the secondary chlorines of PVC facilitates grafting of a sulfonated monomer. A series of proton conducting graft copolymer electrolyte membranes, i.e. poly(vinyl chloride)‐g‐poly(styrene sulfonic acid) (PVC‐g‐PSSA) were prepared by ATRP using direct initiation of the secondary chlorines of PVC. The successful syntheses of graft copolymers were confirmed by 1H‐NMR and FT‐IR spectroscopy. The images of transmission electron microscopy (TEM) presented the well‐defined microphase‐separated structure of the graft copolymer electrolyte membranes. All the properties of ion exchange capacity (IEC), water uptake, and proton conductivity for the membranes continuously increased with increasing PSSA contents. The characterization of the membranes by thermal gravimetric analysis (TGA) also demonstrated their high thermal stability up to 200°C. The membranes were further crosslinked using UV irradiation after converting chlorine atoms to azide groups, as revealed by FT‐IR spectroscopy. After crosslinking, water uptake significantly decreased from 207% to 84% and the tensile strength increased from 45.2 to 71.5 MPa with a marginal change of proton conductivity from 0.093 to 0.083 S cm−1, which indicates that the crosslinked PVC‐g‐PSSA membranes are promising candidates for proton conducting materials for fuel cell applications. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of formulation variables on entrapment efficiency and release characteristics of bovine serum albumin from carboxymethyl xanthan microparticles
Authors: Maiti Sabyasachi , Ray Somasree , Sa Biswanath 
Published: January 2008

AbstractXanthan gum was derivatized to sodium carboxymethyl xanthan (SCMX) gum with a view to prepare bovine serum albumin (BSA)‐loaded carboxymethyl xanthan (CMX) microparticles through interaction with metal ion in a completely aqueous environment. The effect of various formulation variables, such as a pH of SCMX gum solution, concentration of BSA and SCMX gum, and gelation time on BSA entrapment efficiency and release of the protein in different media were studied. While BSA entrapment efficiency was found to decrease with increase in gelation time and initial BSA loading, the same was found to increase with increase in concentration of SCMX gum. Although the release of BSA in acidic medium was almost equal to that in alkaline medium, as compared up to 2 hr, the release in alkaline medium was found to be prolonged to a different extent depending upon the formulation variables. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis of spherical silica particles by sol‐gel method and application
Authors: Fuchigami Kiyomi , Taguchi Yoshinari , Tanaka Masato 
Published: January 2008

AbstractSpherical silica particles were synthesized using the sol‐gel method by hydrolyzing tetraethyl orthosilicate (TEOS) with an alkali catalyst, and it was investigated how the experimental conditions (the reaction temperature, the concentration and dropping rate of the hydrolysis catalyst solution) affected the size and morphology of silica particles. Furthermore, the silica particles were doped with sodium fluoride to measure their ion release ability. The mean diameters of the silica particles changed according to the reaction temperature and the dropping rate of the hydrolysis catalyst, namely the higher the reaction temperature or the slower the dropping rate the smaller are the mean diameters. The surface area of the silica particles was significantly different depending on the dropping rate of the hydrolysis catalyst, namely the slower the dropping rate the larger the specific surface area. The specific heat capacity and thermal reduction (TG) of the silica particles were significantly different according to the reaction temperature, namely the higher the reaction temperature the lower the specific heat capacity and the TG. It was found that the fluoride‐retaining ability was proportional to the surface area of silica particles. The fluoride ion release was equilibrated on elapsing 5 min. Copyright © 2008 John Wiley & Sons, Ltd.
Schiff base substitute polyphenol and its metal complexes derived from o‐vanillin with 2,3‐diaminopyridine: synthesis, characterization, thermal, and conductivity properties
Authors: Kaya İsmet , Bilici Ali , Gül Murat 
Published: January 2008

AbstractPoly‐2,3‐bis[(2‐hydroxy‐3‐methoxyphenyl)methylene]diamino pyridine (PHMPMDAP) that a new Schiff base polymer has been synthesized and characterized by spectroscopy, elemental, and thermal analyses techniques. This azomethine polymer was found to form complexes readily with Cu(II), Zn(II), Co(II), Pb(II), and Fe(II). From IR and UV‐Vis studies, the phenolic oxygen and imine nitrogen of the ligand were found to be the coordination sites. Thermogravimetric analysis (TGA) data indicate the polymer to be more stable than the monomer. The structure of the polymer obtained was confirmed by FT‐IR, UV‐Vis, 13C‐NMR, and 1H‐NMR. Characterization was undertaken by TGA, size exclusion chromatography (SEC), and solubility tests. Also, electrical conductivities of PHMPMDAP and polymer–metal complexes are measured by four probe technique. Copyright © 2008 John Wiley & Sons, Ltd.
High‐performance polyimide–clay nanocomposite materials based on a dual intercalating agent system
Authors: Huang Chao‐Cheng , Jang Guang‐Way , Chang Kung‐Chin , Hung Wei‐I , Yeh Jui‐Ming 
Published: January 2008

AbstractBACKGROUND: Polymer–clay nanocomposites (PCNs) have attracted considerable interest in recent years owing to their unique physical and chemical properties that lead to a wide range of applications. A series of PCN materials consisting of polyimide and layered montmorillonite (MMT) clay were successfully prepared by in situ polymerization.RESULTS: Silicate layers are better dispersed in polymer matrices when dual intercalating agents (hexadecyltrimethylammonium bromide–4,4′‐oxydianiline) are applied for MMT modification according to wide‐angle X‐ray diffraction and transmission electron microscopy studies. Effects of single and dual intercalating agents on thermal stability, mechanical strength and the molecular barrier of PCN materials consisting of organo‐modified MMT were studied by means of thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analyses, gas permeability analysis and vapor permeability analysis.CONCLUSION: Improved thermal and mechanical stabilities, as well as barrier properties were observed for the PCN materials containing dual intercalating agent‐modified MMT. Copyright © 2008 Society of Chemical Industry