bluuebunny/crossref_metadata_2025 huggingface dataset:
Spinocerebellar ataxia type 17: Extension of phenotype with putaminal rim hyperintensity on magnetic resonance imaging
Authors: Loy Clement T. , Sweeney Mary G. , Davis Mary B. , Wills Adrian J. , Sawle Guy V. , Lees Andrew J. , Tabrizi Sarah J.
Published: July 2005

We report on a 50‐year‐old woman who presented with an 8‐year history of involuntary movements, unsteadiness, and cognitive decline. Examination revealed multidomain cognitive deficits, jerky ocular pursuit movements, hypometric saccades, gaze impersistence, dysarthria, upper limb dystonia, and widespread chorea. TATA‐binding protein gene test revealed trinucleotide expansion allele sizes of 47 and 39 repeats, confirming the diagnosis of spinocerebellar ataxia type 17 (SCA‐17). Magnetic resonance imaging (MRI) showed marked cerebellar atrophy and putaminal rim hyperintensity. This is the first case of SCA‐17 reported to show MRI signal change in the basal ganglia, and extends the phenotypic manifestation of SCA‐17. © 2005 Movement Disorder Society
Clinical feature profile of spinocerebellar ataxia type 1–8 predicts genetically defined subtypes
Authors: Maschke Matthias , Oehlert Gary , Xie Ting‐Dong , Perlman Susan , Subramony Sub H. , Kumar Neeraj , Ptacek Louis J. , Gomez Christopher M.
Published: July 2005

An increasing number of genetically defined types of spinocerebellar ataxia (SCA) have been reported in the past decade. Phenotype–genotype correlation studies have suggested a broad overlap between SCA types. The aim of the present study was to identify patterns of clinical features that were likely to distinguish between SCA types and to test the specificity and sensitivity of these signs and symptoms using a Bayesian classifier. In total, 127 patients from 50 families with SCA types 1 to 8 were examined using a worksheet with a panel of 33 symptoms and signs. By computing the probabilities of each trait for each SCA type, we rated the predictive value of each feature for each form of ataxia and then combined the probabilities for the entire panel of traits to construct a Bayesian classifier. Results of this analysis were summarized in a simpler, more operator‐based algorithm. Patients with SCA5, SCA6, and SCA8 demonstrated a predominant cerebellar syndrome, whereas patients with SCA1, SCA2, SCA3, SCA4, and SCA7 frequently had clinical features indicating an extracerebellar involvement. The Bayesian classifier predicted the SCA type in 78% of patients with sensitivities between 60 and 100% and specificities between 94 and 98.2%. The highest sensitivity to correctly predict the true SCA type was found for SCA5, SCA7, and SCA8. Sensitivities and specificities found in the present study validate the use of algorithms to help to prioritize specific SCA gene testing, which will help to reduce costs for gene testing. © 2005 Movement Disorder Society
Efficient internal pallidal stimulation in Gilles de la Tourette syndrome: A case report
Authors: Diederich Nico J. , Kalteis Karin , Stamenkovic Mara , Pieri Vannina , Alesch François
Published: July 2005

The usefulness of deep brain stimulation (DBS) of thalamic nuclei in Gilles de la Tourette syndrome (GTS) has recently been advocated. We report on a 14‐month follow‐up study of a patient with intractable GTS in whom bilateral DBS of the internal globus pallidus was carried out. Tic frequency per minute decreased by 73% in the postoperative phase and in particular the vocal tics became less intense. Pronation/ supination bradykinesia of the left extremities was a well‐tolerated, permanent side effect. Pallidal DBS could become a valuable rescue therapy for otherwise intractable GTS. © 2005 Movement Disorder Society
Paraneoplastic chorea with leukoencephalopathy presenting with obsessive–compulsive and behavioral disorder
Authors: Muehlschlegel Susanne , Okun Michael S. , Foote Kelly D. , Coco Dominique , Yachnis Anthony T. , Fernandez Hubert H.
Published: July 2005

Chorea is a rare manifestation of paraneoplastic disease and is associated with CV2/CRMP‐5 antibodies. Obsessive–compulsive disorder and large‐scale white matter abnormalities on MRI have not been previously reported in association with these antibodies. We report on a case of CV2 paraneoplastic syndrome with obsessive–compulsive behavior preceding the motor manifestations of chorea with associated leukoencephalopathy on MRI. The literature on paraneoplastic chorea is reviewed. © 2005 Movement Disorder Society
Sonographic assessment of urinary retention in multiple system atrophy and idiopathic Parkinson's disease
Authors: Hahn Kirsten , Ebersbach Georg
Published: July 2005

Sonography of the bladder was performed before and after voluntary voiding in 20 subjects with possible/probable multiple system atrophy (MSA), 20 patients with idiopathic Parkinson's disease (PD), and 20 healthy controls. Mean residual volume was 173 ml (SD, 194) in MSA and significantly increased compared to both PD (21 ml; SD, 49) and controls (13 ml; SD, 12). Incomplete voiding (>100 ml of residual volume) was found in 11 subjects with MSA but only in 1 patient with PD. Positive predictive value of increased residual volume for MSA was 91.6% in this study, whereas negative predictive value was only 67.8. Bladder sonography is an objective, simple, and safe tool that allows one to screen for urinary retention, which is highly suggestive but incompletely sensitive for MSA. Because sonography is easily accessible and rapidly performed, it is feasible for routine assessment of atypical Parkinsonism. © 2005 Movement Disorder Society
Clinical and neurophysiologic spectrum of orthostatic tremor: Case series of 26 subjects
Authors: Piboolnurak Panida , Yu Qiping P. , Pullman Seth L.
Published: July 2005

Orthostatic tremor (OT) is a condition described as high‐frequency tremors predominantly in the legs and trunk, which are present not only in the standing position but also during isometric contraction of the limb muscles. This report is one of the largest OT series describing clinical and neurophysiologic findings in 26 subjects with OT. The main findings included 13.0 to 18.6 Hz leg tremors while standing with varied patterns of phase relationships between the antagonists of the ipsilateral leg and between the homologous muscles of the contralateral leg, short latency tremor onset upon standing with abrupt cessation after sitting, coexistence of tremors in the cranial structures and the arms, and sense of unsteadiness without actual falls. Although the oscillator of OT is most likely located in the brainstem, cerebral cortex, basal ganglia, and cerebellum may also be involved in its pathogenesis. © 2005 Movement Disorder Society
Suboptimal medication adherence in Parkinson's disease
Authors: Grosset Katherine A. , Bone Ian , Grosset Donald G.
Published: July 2005

Patients take less medication than prescribed in many disease areas but evidence for suboptimal therapy adherence in Parkinson's disease (PD) is limited. A single‐center observational study of antiparkinsonian medication was undertaken using electronic monitoring (MEMS; Aardex, Zug, Switzerland) over 3 months. Of 68 patients approached, 6 declined and 8 dropped out, leaving 54 patients (taking 117 preparations) with available data. Poorer compliance was associated significantly with younger age, with taking more antiparkinsonian tablets per day, with higher depression scores, and with poorer quality of life. Of the 54 evaluable patients, 11 (20%) had average total compliance of under 80% (underusers) and 43 (80%) had average total compliance of over 80% (satisfactory adherence). Underusers had median total compliance of 65% (interquartile range, 37–74) versus 98% (interquartile range, 93–102) in the satisfactory adherence group. Timing compliance (number of doses taken in the correct time interval) was poor in both underusers (median, 11%; interquartile range, 2–20) and those with satisfactory adherence (median, 25%; interquartile range, 11–73). In conclusion, poorer compliance is associated with younger age, depression, and more tablets per day, and one‐fifth of PD patients underuse medication. Consideration of drug therapy adherence has implications in the management of PD. © 2005 Movement Disorder Society
Burden of disease related to Parkinson's disease in Spain in the year 2000
Authors: Cubo Esther , Alvarez Elena , Morant Consuelo , De Pedro Cuesta Jesús , Martínez Martín Pablo , Génova Ricard , Freire José Manuel
Published: July 2005

We measured the burden caused by Parkinson's disease (PD) in Spain during the year 2000 and compared it against PD burden worldwide and in the European A subregion. Burden of disease (BoD) is an important factor in health policy. Disability‐adjusted life years (DALY) as a measure of BoD is the result of adding years of life lost (YLL) and years lived with disability (YLD). The burden of PD (BPD) has not been studied in Spain. YLL were obtained from the Spanish death certificates and YLD from the estimated number of incident PD cases and the average PD duration. PD disability was calculated, using the Disability Weights for Diseases in the Netherlands. Prior PD DALY data for Europe and the world were obtained from the 2001 World Health Organization World Health Report. A discount rate of 3% and age‐weighting modulation factor with K = 1 were used. In Spain, PD generated 67,582 DALY, comprising 6,351 (9.4%) YLL and 61,231 (90.6%) YLD. Most PD DALY (57.5%) occurred in the population 60 to 74 years of age. When PD DALY estimates were adjusted using the world population in 2000, Spain registered a PD DALY rate of 84 per 100,000 population, higher than both the world and European A subregion rates (24 and 35 per 100,000 population, respectively). PD burden in Spain in 2000 was high, with disability being the major contributing factor. Although BPD in Spain was greater than both world and European A subregion BPD, these differences should nevertheless be interpreted with caution. © 2005 Movement Disorder Society
Cancer cell‐secreted proteomes as a basis for searching potential tumor markers: Nasopharyngeal carcinoma as a model
Authors: Wu Chih‐Ching , Chien Kun‐Yi , Tsang Ngan‐Ming , Chang Kai‐Ping , Hao Sheng‐Po , Tsao Chuang‐Hui , Chang Yu‐Sun , Yu Jau‐Song
Published: July 2005

Nasopharyngeal carcinoma (NPC) is commonly diagnosed late due to its deep location and vague symptoms. To identify biomarkers for early NPC diagnosis, secreted proteomes of two NPC cell lines were analyzed. Proteins in the NPC cell‐line cultured media were systematically identified by SDS‐PAGE combined with MALDI‐TOF MS. Twenty‐three proteins were found in cultured media from both NPC cell lines. Among them, fibronectin, Mac‐2 binding protein (Mac‐2 BP), and plasminogen activator inhibitor 1 (PAI‐1) were further confirmed by Western blot analysis. These three proteins were highly expressed in NPC biopsies, but weakly or not expressed in normal nasopharyngeal tissues. The serum levels of the three proteins were significantly higher in NPC patients (n = 46) than in normal controls (n = 47) (p < 0.01). NPC nude mice model (n = 9) also showed elevated levels of serum Mac‐2 BP and PAI‐1 compared with tumor‐free mice (n = 9) (p < 0.01). Systematic analysis of cancer cell‐secreted proteomes combined with animal tumor models can be a feasible, convenient strategy for searching multiple potential tumor markers. Furthermore, our work shows that fibronectin, Mac‐2 BP, and PAI‐1 may be potential markers for diagnosis of NPC.
Analysis of secreted proteins from Aspergillus flavus
Authors: Medina Martha L. , Haynes Paul A. , Breci Linda , Francisco Wilson A.
Published: July 2005

MS/MS techniques in proteomics make possible the identification of proteins from organisms with little or no genome sequence information available. Peptide sequences are obtained from tandem mass spectra by matching peptide mass and fragmentation information to protein sequence information from related organisms, including unannotated genome sequence data. This peptide identification data can then be grouped and reconstructed into protein data. In this study, we have used this approach to study protein secretion by Aspergillus flavus, a filamentous fungus for which very little genome sequence information is available. A. flavus is capable of degrading the flavonoid rutin (quercetin 3‐O‐glycoside), as the only source of carbon via an extracellular enzyme system. In this continuing study, a proteomic analysis was used to identify secreted proteins from A. flavus when grown on rutin. The growth media glucose and potato dextrose were used to identify differentially expressed secreted proteins. The secreted proteins were analyzed by 1‐ and 2‐DE and MS/MS. A total of 51 unique A. flavus secreted proteins were identified from the three growth conditions. Ten proteins were unique to rutin‐, five to glucose‐ and one to potato dextrose‐grown A. flavus. Sixteen secreted proteins were common to all three media. Fourteen identifications were of hypothetical proteins or proteins of unknown functions. To our knowledge, this is the first extensive proteomic study conducted to identify the secreted proteins from a filamentous fungus.
Chromatofocusing fractionation and two‐dimensional difference gel electrophoresis for low abundance serum proteins
Authors: Qin Shuzhen , Ferdinand Angeline S. , Richie Jerome P. , O'Leary Michael P. , Mok Samuel C. , Liu Brian C.‐S.
Published: July 2005

The technical challenge to analysis of the serum proteome is that the serum proteins are present at unequal concentrations. A few are so dominant, such as serum albumin and immunoglobulins, that they mask detection of other proteins. Because of these high abundance proteins, current technologies, while theoretically capable of analyzing protein amounts spanning four orders of magnitude, are only able to analyze proteins ranging over two orders of magnitude and cannot analyze the lower abundance proteins that may be the next biomarkers and drug targets. To facilitate the identification of low abundance proteins, we fractionated serum samples from patients with prostate cancer and patients with benign prostate hyperplasia using anion displacement liquid chromatofocusing chromatography, which separates proteins by a pH gradient and a positively charged column. Differential expression of proteins from fractions was then determined and identified by IEF gels and 2‐D DIGE. Results demonstrate improved resolution of proteins within the chosen pH gradient when compared to the unfractionated samples. Several proteins that were differentially expressed in serum from patients with prostate cancer were identified in the fractionated serum. Three of these proteins, squamous cell carcinoma antigen 1 (SCCA1), calgranulin B, and haptoglobin‐related protein, are present in the serum at levels below the classical protein level of mg/mL. SCCA1 is normally expressed in serum at ng/mL levels, and calgranulin B is an intracellular protein. Our results demonstrate that the use of anion displacement liquid chromatofocusing chromatography may reduce the complexity of the serum proteome by separating proteins into distinct pH ranges, and facilitate the identification of low abundance proteins.
Proteomic characterization of human normal articular chondrocytes: A novel tool for the study of osteoarthritis and other rheumatic diseases
Authors: Ruiz‐Romero Cristina , López‐Armada María J. , Blanco Francisco J.
Published: July 2005

Articular cartilage is composed of cells and an extracellular matrix. The chondrocyte is the only cell type present in mature cartilage, and it is important in the control of cartilage integrity. There is currently a great lack of knowledge about the chondrocyte proteome. To solve this deficiency, we have obtained the first reference map of the human normal articular chondrocyte. Cells were isolated from cartilages obtained from autopsies without history of joint disease. Cultured cells were used to obtain protein extracts which were resolved by 2‐DE and visualized by silver nitrate or CBB staining. Almost 200 spots were excised from the gels and analyzed using MALDI‐TOF or MALDI‐TOF/TOF MS. The analysis leads to the identification of 136 spots that represent 93 different proteins. A significant proportion of proteins are involved in cell organization (26%), energy (16%), protein fate (14%), metabolism (12%), and cell stress (12%). From all the identified proteins, annexins, vimentin, transgelin, destrin, cathepsin D, heat shock protein 47, and mitochondrial superoxide dismutase were more abundant in chondrocytes than in other types of mesenchymal cells such as Jurkat‐T cells. As metabolic program of chondrocytes is altered in osteoarthritis and other rheumatic diseases, this proteomic map is an important tool for future studies on these pathologies.
Maximising sensitivity for detecting changes in protein expression: Experimental design using minimal CyDyes
Authors: Karp Natasha A. , Lilley Kathryn S.
Published: July 2005

DIGE is a powerful tool for measuring changes in protein expression between samples. Here we assess the assumptions of normality and heterogeneity of variance that underlie the univariate statistical tests routinely used to detect proteins with expression changes. Furthermore, the technical variance experienced in a multigel experiment is assessed here and found to be reproducible within‐ and across‐sample types. Utilising the technical variance measured, a power study is completed for several ‘typical’ fold changes in expression commonly used as thresholds by researchers. Based on this study using DeCyder, guidance is given on the number of gel replicates that are needed for the experiment to have sufficient sensitivity to detect expression changes. A two‐dye system based on utilising just Cy3 and Cy5 was found to be more reproducible than the three‐dye system. A power and cost‐benefit analysis performed here suggests that the traditional three‐dye system would use fewer resources in studies where multiple samples are compared. Technical variance was shown to encompass both experimental and analytical noise and thus is dependent on the analytical software utilised. Data is provided as a resource to the community to assess alternative software and upgrades.
Sociomics! Using the IssueCrawler to map, monitor and engage with the global proteomics research network
Authors: McNally Ruth
Published: July 2005

We invite comment upon an experiment to locate proteomics on the WWW using a software tool called the IssueCrawler. We call our research “sociomics” because, like the bioscience omics, it is a semi‐automated, computerised approach to the global analysis of data, whose computerised results can be integrated towards the development of a new “systems sociology” approach to the study of society. Our findings are that proteomics on the web is a scale‐free network whose nodes display considerable “dynamic range”.
Synthesis and characterization of novel biodegradable unsaturated poly(ester amide)/poly(ethylene glycol) diacrylate hydrogels
Authors: Guo Kai , Chu C. C.
Published: July 2005

A series of novel biodegradable hydrogels were designed and synthesized from four types of unsaturated poly(ester amide) (UPEA) and poly(ethylene glycol) diacrylate (PEG‐DA) precursors by UV photocrosslinking. These newly synthesized biodegradable UPEA/PEG‐DA hydrogels were characterized by their gel fraction (Gf), equilibrium swelling ratio (Qeq), compressive modulus, and interior morphology. The effect of the precursor feed ratio (UPEAs to PEG‐DA) on the properties of the hydrogels was also studied. The incorporation of UPEA polymers into the PEG‐DA hydrogels increased their hydrophobicity, crosslinking density (denser network), and mechanical strength (higher compressive modulus) but reduced Qeq. When different types of UPEA precursors were coupled with PEG‐DA at the same feed ratio (20 wt %), the resulting hydrogels had similar Qeq values and porous three‐dimensional interior morphologies but different Gf and compressive modulus values. These differences in the hydrogel properties were correlated to the chemical structures of the UPEA precursors; that is, the different locations of the >CC< double bonds in individual UPEA segments resulted in their different reactivities toward PEG‐DA to form hydrogels. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3932–3944, 2005
Synthesis of ionic polyurethanes with pyrene rings: Spectral properties and fluorescence quenching study
Authors: Buruiana Emil C. , Buruiana Tinca , Strat Georgeta , Strat Mitachi
Published: July 2005

Hydrophilic ionic polyurethanes with 4‐chloromethylphenylcarbamoyl‐1‐oxymethylpyrene located on the quaternary ammonium structure from a polymer based on poly(ethylene glycol), isophorone diisocyanate, and N‐methyldiethanolamine were prepared by a quaternization reaction, in which the amount of pyrene covalently attached to the polymeric backbone ranged from 1.14 to 19.82 mmol of fluorophore/100 g of polymer. It was interesting to compare the photoluminescence of the pyrene polyurethane carrying a few mole percent of pyrene moieties with that of a third polymer resulting from its subsequent quaternization with benzyl chloride up to a concentration of ionic groups as in the latter (quaternization degree = 14.15%). The process of excimer formation between the pyrene molecules attached to the ionic polyurethane was investigated in tetrahydrofuran (THF), dimethylformamide, film, and THF/H2O to illustrate the expected differences in the polymer behavior compared with that of the starting pyrene derivative. The formation of aggregates or core–shell micelles was sustained by the fluorescence data, which indicated the existence of pyrene units in the ground state of the molecule, giving rise thus to an explanation for the high excimer‐to‐monomer intensity ratio. The fluorescence decay of pyrene polyurethanes in the presence of various concentrations of nitrobenzene used as a quencher was analyzed too when the fluorescence quenching in the polymer solution normally followed Stern–Volmer kinetics. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3945–3956, 2005
Polymerization of n‐phenyl maleimide by lanthanide complexes
Authors: Zhao Bei , Wang Yaorong , Lu Chengrong , Shen Qi , Deng Mingyu
Published: July 2005

N‐Phenyl maleimide (N‐PMI) was successfully polymerized by divalent rare‐earth complexes (ArO)2Sm(THF)4 (ArO = 2,6‐di‐tert‐butyl‐4‐methyl phenoxo‐; THF = tetrahydrofuran) and (Ar′O)2Ln(THF)3 (Ar′O = 2,6‐di‐tert‐butyl phenoxo‐; Ln = Sm, Yb, or Eu). The central metals greatly affected the reactivity, and the reactivity order was Sm(II) > Yb(II) > Eu(II). The activity of (Ar′O)2Sm(THF)3 was higher than that of (ArO)2Sm(THF)4. The polymerization yields were higher in THF than in other solvents, and the maximum yields were obtained around 25 °C. A proposed mechanism is discussed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3966–3972, 2005
Posttraumatic growth in prostate cancer survivors and their partners
Authors: Thornton Andrea A. , Perez Martin A.
Published: July 2005

We examined posttraumatic growth (PTG) in men treated for prostate cancer and their partners 1 year after surgery. Levels of PTG in prostate cancer survivors and their partners were similar and modest. For survivors, higher levels of presurgery negative affect, and coping by using positive reframing and emotional support were associated with higher levels of PTG 1 year following surgery. For partners, PTG 1 year after the patient's surgery was higher in partners who were partnered to employed patients, were less educated, endorsed higher cancer‐specific avoidance symptoms of stress at presurgery, and used positive reframing coping. Quality of life was largely unrelated to PTG in survivors or partners. Findings suggest that psychological disruption associated with the cancer experience and coping are related to PTG in prostate cancer survivors and their partners. Copyright © 2005 John Wiley & Sons, Ltd.
Study on mechanism of soft magnetic properties for high‐frequency application in Ni75Fe25–SiO2 granular films
Authors: Ge Shihui , Yang Xiaolin , Youn Kim Kwang , Xi Li , Kou Xiaoming , Yao Dongsheng , Li Binsheng , Wang Xinwei
Published: July 2005

Excellent soft magnetic properties have been achieved in a wide metal volume fraction (x) range for as‐deposited (Ni75Fe25)x–(SiO2)(1–x) granular films fabricated by magnetron sputtering. With x changes from 0.81 to 0.52, the films exhibit small coercivity (Hc) not exceeding 5 Oe and high electrical resistivity ρ. The minimum Hc value of 87.6 A m–1 was obtained for the sample of x = 0.81. At the frequency lower than 550 MHz, the real part μ′ of complex permeability keeps about 170 and the image part μ″ is less than 26. Especially, for the film with very low x (= 0.52), besides the low Hc (∼3 Oe), very high ρ over 1.18 × 104 μΩ cm has been obtained. A combined study of TEM and XRD indicates that the samples consist of Ni75Fe25 particles uniformly embedded in insulating SiO2 matrix. The excellent soft magnetic property is ascribed to the exchange coupling among magnetic particles due to the long exchange length of Ni75Fe25. The investigation of the Henkel plot evidences the existence of this intergranular interaction. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structure and magnetic properties of TbCo7–xMx
Authors: Guo Yongquan , Feng Weicun , Luo Jun , Liang Jingkui , Yu Xiaojun , Li Wei
Published: July 2005

A novel intermetallic compound, TbCo7–xMx (M = 3d transition metal or normal metal), has been successfully synthesized. TbCo7–xMx crystallizes in a hexagonal TbCu7 structure with space group of P6/mmm. According to the structural refinement, the M dopants occupy the 2e and 3g crystal positions based on their electronegativities. TbCo7–xMx exhibits ferromagnetic order. The saturation moment has been calculated with a corrected magnetic valence model; the calculated results agree well with experiment. The correction to the structural stability model of TbCo7–xMx has been discussed in terms of the effective atomic radius ratio and the difference of electronegativity between Tb and (Co, M). (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray investigations of nanopowder WO3 thick films
Authors: Khatko V. , Guirado F. , Hubalek J. , Llobet E. , Correig X.
Published: July 2005

Nanoparticle tungsten trioxide thick films based on commercial WO3 nanopowder and powder mixtures with different concentrations of metals (Ag, In and Bi) were prepared by screen‐printing onto alumina substrates. The changes in phase composition, crystallite size and cell parameters induced in tungsten trioxide thick films by the inclusion of metal impurities were investigated by X‐ray diffraction (XRD). Some of the samples were further analysed using a high temperature XRD method. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phonon modes of monoclinic BiB3O6
Authors: Gössling A. , Möller T. , Stein W.‐D. , Becker P. , Bohatý L. , Grüninger M.
Published: July 2005

We present a detailed study of the phonon modes of the monoclinic compound BiB3O6 based on polarized reflectivity measurements on single crystals.

The spectra are analysed by means of a generalized Drude–Lorentz model, which allows us to resolve the modes of A and B symmetry. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Density functional theory of the iron–nitrosyl (S = 3/2) complex
Authors: Cheng Hsiu‐Yao , Chang Shyang
Published: July 2005

On the basis of density functional theory (DFT), the iron–nitrosyl complex Fe[Me3TACN](NO)(N3)2 (S = 3/2) is studied via the B3LYP hybrid method. Its Raman vibrational frequencies, atomic net charges, and spin densities are analyzed. The related complexes Fe(NH3) (n = 1, 2, and 3) are employed as reference compounds to determine the characteristics of the central iron. Our results indicate that the S = 3/2 spin ground state of Fe[Me3TACN](NO)(N3)2 is best described by the presence of FeII (S = 2) anti‐ferromagnetically coupled to NO0 (S = 1/2) yielding FeII[Me3TACN](NO0)(N)2. This is clearly different from the previous FeIII‐NO− theoretical assignment. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Behavior of the Dirichlet boundary for wave functions in a class of singular potentials
Authors: Bandyopadhyay S. K. , Bhattacharyya K.
Published: July 2005

Variational studies on spiked oscillators with the potential form x2 + λ/xβ in [0, ∞) reveal certain limitations of the conventional choices for wave functions in the β ≥ 2 regime. A careful analysis shows the necessity of properly incorporating the Dirichlet boundary condition at x = 0. Subsequent pilot calculations on this notion perform nicely, justifying the worth of the endeavor. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Spectral techniques applied to sparse random graphs
Authors: Feige Uriel , Ofek Eran
Published: July 2005

We analyze the eigenvalue gap for the adjacency matrices of sparse random graphs. Let λ1 ≥ … ≥ λn be the eigenvalues of an n‐vertex graph, and let λ = max[λ2,|λn|]. Let c be a large enough constant. For graphs of average degree d = c log n it is well known that λ1 ≥ d, and we show that $\lambda = O(\sqrt{d})$. For d = c it is no longer true that $\lambda = O(\sqrt{d})$, but we show that by removing a small number of vertices of highest degree in G, one gets a graph G′ for which $\lambda = O(\sqrt{d})$. Our proofs are based on the techniques of Friedman Kahn and Szemeredi from STOC 1989, who proved similar results for regular graphs. Our results are useful for extending the analysis of certain heuristics to sparser instances of NP‐hard problems. We illustrate this by removing some unnecessary logarithmic factors in the density of k‐SAT formulas that are refuted by the algorithm of Goerdt and Krivelevich from STACS 2001. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2005
Gompertz kinetics model of fast chemical neurotransmission currents
Authors: Easton Dexter M.
Published: July 2005

At a chemical synapse, transmitter molecules ejected from presynaptic terminal(s) bind reversibly with postsynaptic receptors and trigger an increase in channel conductance to specific ions. This paper describes a simple but accurate predictive model for the time course of the synaptic conductance transient, based on Gompertz kinetics. In the model, two simple exponential decay terms set the rates of development and decline of transmitter action. The first, r, triggering conductance activation, is surrogate for the decelerated rate of growth of conductance, G. The second, r′, responsible for Y, deactivation of the conductance, is surrogate for the decelerated rate of decline of transmitter action. Therefore, the differential equation for the net conductance change, g, triggered by the transmitter is dg/dt = g(r−r′). The solution of that equation yields the product of G(t), representing activation, and Y(t), which defines the proportional decline (deactivation) of the current. The model fits, over their full‐time course, published records of macroscopic ionic current associated with fast chemical transmission. The Gompertz model is a convenient and accurate method for routine analysis and comparison of records of synaptic current and putative transmitter time course. A Gompertz fit requiring only three independent rate constants plus initial current appears indistinguishable from a Markov fit using seven rate constants. Synapse 58:53–61, 2005. © 2005 Wiley‐Liss, Inc.
Increased AMPA GluR1 receptor subunit labeling on the plasma membrane of dendrites in the basolateral amygdala of rats self‐administering morphine
Authors: Glass Michael J. , Kruzich Paul J. , Colago Eric E.O. , Kreek Mary Jeanne , Pickel Virginia M.
Published: July 2005

Glutamate‐dependent synaptic plasticity is emerging as an important neural substrate of addiction. These drug‐dependent neural adaptations may occur within brain systems that mediate reward, emotion, and cognitive function such as the amygdala complex. Modification of glutamate receptor targeting may be a key mechanism mediating neural plasticity; however, evidence for alteration of amygdala AMPA receptor localization in response to drug self‐administration is lacking. High‐resolution immunogold electron microscopic immunocytochemistry was used to compare surface and intracellular labeling of the calcium sensitive AMPA GluR1 receptor subunit in the basolateral (BLA) and central (CeA) nuclei of the amygdala in rats self‐administering escalating doses of morphine or saline. Morphine self‐administration was associated with regionally diverse effects on dendritic GluR1 targeting in the BLA and CeA. In the BLA of morphine self‐administering animals, there was a significant increase in the proportion of immunogold particles for GluR1 on the plasma membrane of dendrites, particularly in association with extrasynaptic sites, which was most prominent in large (2–4 μm) profiles. In contrast, there were no significant differences in surface or intracellular immunogold labeling in the CeA between morphine self‐administering and control animals. In both amygdala regions, GluR1 and the μ‐opioid receptor, the major cellular target of morphine, were only infrequently colocalized. These results indicate that GluR1 targeting is a dynamic process that can be differentially affected in distinct amygdala regions in response to chronic self‐administration of morphine. Homeostatic adaptations in the subcellular localization of calcium sensitive AMPA receptors within the BLA may be an important neural substrate for alterations in reward, autonomic function, and behavioral processes associated with opiate addiction. Synapse 58:1–12, 2005 © 2005 Wiley‐Liss, Inc.
Expanded mesencephalic precursors develop into grafts of densely packed dopaminergic neurons that reinnervate the surrounding striatum and induce functional responses in the striatal neurons
Authors: Rodriguez‐Pallares J. , Parga J.A. , Rey P. , Guerra M.J. , Labandeira‐Garcia J.L.
Published: July 2005

The search for alternative sources of dopaminergic cells, other than primary fetal tissue for transplantation in Parkinson's disease has become a major focus of research. Different methodological approaches have led to generation in vitro of cells expressing DA‐cell markers, although these cells are frequently unable to survive for a long time in vivo after transplantation and/or induce functional effects in the host brain. In the present study, we grafted cell aggregates treated with antibodies against fibroblast growth factor 4 into dopaminergic‐denervated striata in rats. Furthermore, we grafted cell suspensions from primary mesencephalic fetal tissue. Grafts from expanded precursors were able to survive (at least 3 months postgrafting) and most decreased the lesion‐induced ipsiversive rotation. In addition, immunolabeling for tyrosine hydroxylase and/or Fos showed that the grafts reinnervated the surrounding striatal tissue with dopaminergic terminals, and induced the expression of Fos in the striatal neurons of the reinnervated area after administration of amphetamine to the host rat. The number of dopaminergic cells in grafts from expanded precursors inducing rotational recovery was usually lower (1,226 ± 314) than that in grafts from primary fetal tissue (1,671 ± 122), but they were more densely packed in grafts that were of smaller volume and did not have the characteristic central nondopaminergic area observed in grafts from primary fetal tissue. The results suggest that long‐term survival and functional integration into the DA‐denervated striatum can be achieved with grafts of expanded mesencephalic precursors. Synapse 58:12–21, 2005. © 2005 Wiley‐Liss, Inc.
Dual synaptic sites of D1‐dopaminergic regulation of ethanol sensitivity of NMDA receptors in nucleus accumbens
Authors: Zhang Tao A. , Hendricson Adam W. , Morrisett Richard A.
Published: July 2005

Regulation of NMDAreceptor‐mediated synaptic transmission onto accumbal medium spiny neurons (MSN) may constitute an important site in drug reward and reinforcement in mesolimbic structures. Previously, we reported that D1‐like dopamine receptors activate a postsynaptic cAMP/PKA/DARPP‐32 signaling cascade culminating in phosphorylation of SER897‐NR1 subunits and a reduction in the sensitivity to ethanol of NMDA receptor‐mediated synaptic transmission. Here, we use a detailed electrophysiological analysis of D1‐like receptor regulation of the ethanol sensitivity of accumbal NMDA receptors (NMDARs) through recordings of quantal Sr2+‐supported NMDA miniature synaptic currents (mEPSCs) in reduced Mg2+ (0.6 mM) and report dual presynaptic and postsynaptic components of D1‐like regulation of ethanol sensitivity of NMDARs. Ethanol inhibited NMDA mEPSC amplitude and frequency in a dose‐dependent manner (25–75 mM), indicating inhibitory effects on presynaptic and postsynaptic components NMDA receptor‐mediated synaptic transmission. The presynaptic inhibitory effect was corroborated by analysing the ratio of paired‐pulse facilitation (PPF) of Ca2+‐supported NMDA EPSCs. Activation of D1 receptors with the agonist, SKF 38393 (25 μM), reversed ethanol suppression of NMDA mEPSC frequency and amplitude. Furthermore, the Mg2+‐dependent decay off‐rate of NMDA mEPSCs was substantially reduced by ethanol in a manner strongly reversed by the D1 agonist. D1 receptor‐mediated attenuation of both the presynaptic and postsynaptic actions of ethanol was completely blocked by a D1 selective antagonist (SCH 23390). These data suggest that D1‐like receptors modulate both the presynaptic and postsynaptic effects of ethanol on NMDA receptor‐mediated synaptic transmission in nucleus accumbens (NAc) and that these interactions may contribute to ethanol‐induced neuroadaptation of the reward pathway. Synapse 58:29–43, 2005. © 2005 Wiley‐Liss, Inc.
Three decades of in vivo x‐ray fluorescence of lead in bone
Authors: Chettle D. R.
Published: July 2005

In vivo measurements of lead in bone were first made in the early 1970s. Of the three systems that have been used (57Co excited K, 125I or polarized excited L, 109Cd excited K), 109Cd excited K x‐ray fluorescence has been most widely adopted. Bone lead measured in vivo has been shown to reflect cumulative exposure, but the rate of input to bone varies with level of exposure. Chelated lead does not relate directly to bone lead. Endogenous exposure has been highlighted by bone lead measurements and this release of lead from bone and hence the half‐life of lead in bone have been shown to depend on age and on intensity of lead exposure. Thus x‐ray spectrometry has made a significant contribution to the understanding of long‐term human lead metabolism. Copyright © 2005 John Wiley & Sons, Ltd.
A new SR‐TXRF vacuum chamber for ultra‐trace analysis at HASYLAB, Beamline L
Authors: Streli C. , Pepponi G. , Wobrauschek P. , Jokubonis C. , Falkenberg G. , Zaray G.
Published: July 2005

A new vacuum chamber for synchrotron radiation‐induced total reflection x‐ray fluorescence (SR‐TXRF) analysis has been installed at HASYLAB, DESY, Hamburg, beamline L utilizing the translation and rotation stages of the regular microfocus setup for adjustment. The chamber is equipped with an automatic sample loader for 30 mm diameter quartz reflectors for inserting the prepared sample reflectors in the measuring position with high reproducibility. Alternatively, a chuck can be inserted allowing various sizes and shapes of samples to be measured. The fluorescence radiation emitted by the sample was measured by a silicon drift detector (SDD) with a 5 mm2 active area and detection limits of 15 fg have been obtained on a sample containing 100 pg of Ni using an Ni/C multilayer monochromator. Using the Si 111 crystal monochromator also x‐ray absorption near edge structure (XANES) investigations in total reflection geometry on trace elements are feasible. Cr K‐edge XANES measurements of C. avellana L. (hazel) pollen (20 ppm Cr concentration) and on an urban aerosol sample are presented. The Cr content in the pollen amounts to about 20 ppm, Detection limits of Cr were found to be 40 pg for a 30 s measuring time, which seems to be reasonable for performing energy scans for x‐ray absorption fine structure measurements. Further, the setup is suitable to perform angle scans to determine depth profiles of implants in Si wafers. This was tested for ultra‐shallow implants of As in Si. Copyright © 2005 John Wiley & Sons, Ltd.
A model system for [NiFe] hydrogenase maturation studies: Purification of an active site‐containing hydrogenase large subunit without small subunit
Authors: Winter Gordon , Buhrke Thorsten , Lenz Oliver , Jones Anne Katherine , Forgber Michael , Friedrich Bärbel
Published: July 2005

The large subunit HoxC of the H2‐sensing [NiFe] hydrogenase from Ralstonia eutropha was purified without its small subunit. Two forms of HoxC were identified. Both forms contained iron but only substoichiometric amounts of nickel. One form was a homodimer of HoxC whereas the second also contained the Ni–Fe site maturation proteins HypC and HypB. Despite the presence of the Ni–Fe active site in some of the proteins, both forms, which lack the Fe–S clusters normally present in hydrogenases, cannot activate hydrogen. The incomplete insertion of nickel into the Ni–Fe site provides direct evidence that Fe precedes Ni in the course of metal center assembly.
Water channel activities of Mimosa pudica plasma membrane intrinsic proteins are regulated by direct interaction and phosphorylation
Authors: Temmei Yusuke , Uchida Shinichi , Hoshino Daisuke , Kanzawa Nobuyuki , Kuwahara Michio , Sasaki Sei , Tsuchiya Takahide
Published: July 2005

cDNAs encoding aquaporins PIP1;1, PIP2;1, and TIP1;1 were isolated from Mimosa pudica (Mp) cDNA library. MpPIP1;1 exhibited no water channel activity; however, it facilitated the water channel activity of MpPIP2;1 in a phosphorylation‐dependent manner. Mutagenesis analysis revealed that Ser‐131 of MpPIP1;1 was phosphorylated by PKA and that cooperative regulation of the water channel activity of MpPIP2;1 was regulated by phosphorylation of Ser‐131 of MpPIP1;1. Immunoprecipitation analysis revealed that MpPIP1;1 binds directly to MpPIP2;1 in a phosphorylation‐independent manner, suggesting that phosphorylation of Ser‐131 of MpPIP1;1 is involved in regulation of the structure of the channel complex with MpMIP2;1 and thereby affects water channel activity.
Inhibitor‐assisted refolding of protease: A protease inhibitor as an intramolecular chaperone
Authors: Kojima Shuichi , Iwahara Akane , Yanai Hideyuki
Published: July 2005

Pleurotus ostrearus proteinase A inhibitor 1 (POIA1), which was discovered as a protease inhibitor, is unique in that it shows sequence homology to the propeptide of subtilisin, which functions as an intramolecular of a cognate protease. In this study, we demonstrate that POIA1 can function as an intramolecular chaperone of subtilisin by in vitro and in vivo experiments. The specific cleavage between POIA1 and the mature region of subtilisin BPN′ occurred in a refolding process of a chimera protein, and Bacillus cells transformed with a chimera gene formed a halo on a skim milk plate. The mutational analyses of POIA1 in the chimera protein suggested that the tertiary structure of POIA1 is required for such a function, and that an increase in its ability to bind to subtilisin BPN′ makes POIA1 a more effective intramolecular chaperone.
In search of a residual dividend policy
Authors: Baker H. Kent , Smith David M.
Published: July 2005

We survey 309 sample firms exhibiting behavior consistent with a residual dividend policy and their matched counterparts to learn how they set their dividend policies. The findings reveal that the sample firms are more likely than their counterparts to maintain a long‐term dividend payout ratio, use long‐run earnings forecasts in setting the dividend, and be unconcerned about the cost of raising external funds. Yet, firms behaving as though they follow a residual dividend policy generally do not profess to follow the policy. At best, the sample firms follow a “modified” residual policy in which they carefully manage their payout ratio and dividend trend. Although it may not be an explicit goal of such a dividend policy, consistently low free cash flow typically results.
Globalization and portfolio risk over time: The role of exchange rate
Authors: Fooladi Iraj J. , Rumsey John
Published: July 2005

We examine benefits of international diversification for the period 1 January 1988 to 30 June 2000. We introduce a new variable (lambda) that measures these benefits more directly than do the pairwise correlations among equity markets, which are used in most other studies. Our study shows that despite international integrations, the benefits of international diversification measured in USD persist. Using lambda, we provide evidence that the increase in co‐movements between equity market returns (measured in local currencies) has been counterbalanced by movements in exchange rates. We confirm our results by subjecting the trend in lambda to several tests.
A Speleothem Record of Younger Dryas Cooling, Klamath Mountains, Oregon, USA
Authors: Vacco David A. , Clark Peter U. , Mix Alan C. , Cheng Hai , Edwards R. Lawrence
Published: July 2005

A well-dated δ18O record in a stalagmite from a cave in the Klamath Mountains, Oregon, with a sampling interval of 50 yr, indicates that the climate of this region cooled essentially synchronously with Younger Dryas climate change elsewhere in the Northern Hemisphere. The δ18O record also indicates significant century-scale temperature variability during the early Holocene. The δ13C record suggests increasing biomass over the cave through the last deglaciation, with century-scale variability but with little detectable response of vegetation to Younger Dryas cooling.
Late Cambrian ptychaspidid trilobites from western Utah: implications for trilobite systematics and biostratigraphy
Authors: ADRAIN J. M. , WESTROP S. R.
Published: July 2005

The Notch Peak Formation (Late Cambrian, Sunwaptan) of western Utah yields diverse silicified trilobite faunas that provide new information on the anatomy of many taxa. The family Ptychaspididae Raymond, 1924, is represented by species of Keithiella Rasetti, 1944; Idiomesus Raymond, 1924; Euptychaspis Ulrich in Bridge, 1931; and Macronoda Lochman, 1964. At least four species are new, of which E. lawsonensis and M. notchpeakensis are named formally. Much previous work on Late Cambrian trilobites has emphasized biostratigraphic utility and the recognition of geographically widespread species. Data from new silicified collections indicate that this approach is difficult to justify because many putative ‘index species’ actually represent a plexus of closely related species whose biostratigraphic significance has yet to be determined. One such plexus is represented by E. kirki Kobayashi, 1935, whose previously reported occurrences in Texas, Oklahoma, Utah, Nevada and northern Canada record at least four distinct species. Similarly, Macronoda can now be shown to consist of at least five late Sunwaptan species in south-central and western North America.