bluuebunny/crossref_metadata_2025 huggingface dataset:
Abnormal sleep architecture is an early feature in the E46K familial synucleinopathy
Authors: Zarranz Juan J. , Fernández‐Bedoya Anabel , Lambarri Imanol , Gómez‐Esteban Juan C. , Lezcano Elena , Zamacona Javier , Madoz Pedro
Published: July 2005

We examined 7 patients from a family harboring a novel mutation in the α‐synuclein gene (E46K) that segregated with a phenotype of parkinsonism and dementia with Lewy bodies. An abnormal restless sleep was the presenting symptom in 2 of them. Polysomnographic (PSG) studies were performed in 4 of the 7 patients and in 2 asymptomatic carriers of the mutation. A severe loss of both rapid eye movement (REM) and non‐REM sleep was observed in 2 patients complaining of insomnia and in a third parkinsonian member of the family who did not complain of trouble with sleeping. Another parkinsonian family member had a mild disorganization of the sleep architecture. The 2 asymptomatic carriers also had minor changes in the PSG findings. Episodes of bizarre behavior at night were reported historically in the 2 symptomatic patients, but we did not observed the behaviors during the PSG studies. REM sleep behavior disorder could not be recorded in any case. Our findings expand the spectrum of sleep disorders reported in synucleinopathies whether sporadic or familial. © 2005 Movement Disorder Society
Essential tremor centralized brain repository: Diagnostic validity and clinical characteristics of a highly selected group of essential tremor cases
Authors: Louis Elan D. , Borden Sarah , Moskowitz Carol B.
Published: July 2005

We studied essential tremor (ET) cases enrolled in the Essential Tremor Centralized Brain Repository to (1) assess the validity of their diagnoses and (2) characterize the clinical features in a group of highly selected cases who might reflect a far end of the disease spectrum. Our over‐arching goal was to provide a perspective of ET that complements that derived from population‐based and clinic‐based studies. Based on a history and videotaped examination, 94 of 100 ET cases had their diagnoses confirmed; most of the remainder had Parkinson's disease. When compared with ET cases ascertained through populations and clinics, a large proportion had been prescribed medication for tremor (87.2%), had a family history of tremor (88.3%), had rest tremor (33.0%), or had neck tremor (60.6%). One patient had facial tremor, which has not been reported previously. As has been reported once before, a large proportion wore hearing aids (26.9% of the 67 participants age ≥ 70). In summary, diagnostic validity was high. In terms of their clinical characteristics, the high proportion of cases with severe tremor and varied disease manifestations (neck tremor, rest tremor) make these cases a valuable resource in pathological studies; the high proportion with familial tremor would provide an enriched sample for genetic studies. © 2005 Movement Disorder Society
Throat clicking as the initial symptom of Parkinson's disease
Authors: Iyer Sanjay S. , Morgan John C. , Glover Andrea L. , Sethi Kapil D.
Published: July 2005

The presenting manifestations of Parkinson's disease (PD) are variable, but a majority of patients note tremor as the initial symptom. Others complain of slowing of movements, loss of dexterity, fatigue, or changes in handwriting as initial symptoms. We describe a patient who developed an unusual clicking sound emanating from his throat as the initial manifestation of PD. © 2005 Movement Disorder Society
Preserved cardiac sympathetic nerve accounts for normal cardiac uptake of MIBG in PARK2
Authors: Orimo Satoshi , Amino Takeshi , Yokochi Masayuki , Kojo Tohru , Uchihara Toshiki , Takahashi Atsushi , Wakabayashi Koichi , Takahashi Hitoshi , Hattori Nobutaka , Mizuno Yoshikuni
Published: July 2005

We performed [123I] MIBG myocardial scintigraphy in two of three patients with PARK2 from unrelated families and examined the heart tissues from the three patients immunohistochemically using an antibody against tyrosine hydroxylase (TH) to see whether cardiac sympathetic nerve is involved. Cardiac uptake of MIBG was normal except for a slight decrease in the late phase in one of the patients. Postmortem examination revealed that TH‐immunoreactive nerve fibers in the epicardium were well preserved in all three patients. The present study confirmed that cardiac sympathetic nerve is well preserved in PARK2 with a homozygous exon deletion, which accounts for normal cardiac uptake of MIBG. Moreover, normal cardiac uptake of MIBG might be of potential diagnostic value to indicate the absence of Lewy body pathology, even in patients with levodopa‐responsive Parkinsonism, as in PARK2. © 2005 Movement Disorder Society
Preparation of gradient copolymers via ATRP using a simultaneous reverse and normal initiation process. I. Spontaneous gradient
Authors: Min Ke , Li Mei , Matyjaszewski Krzysztof
Published: July 2005

Spontaneous gradient copolymers were prepared in both bulk and miniemulsion systems via Atom Transfer Radical Polymerization (ATRP) utilizing a Simultaneous Reverse and Normal Initiation (SR & NI) process. Both instantaneous and cumulative compositions were used to characterize the gradient copolymers. The gradient copolymers were obtained with an array of gradient compositions ranging from a subtle to strong variation in monomer distribution along the polymer backbones, depending on the ratio of comonomers initially added to the copolymerization system. The compositions of the gradient copolymer produced in miniemulsion systems were similar to those generated in bulk. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3616–3622, 2005
Preparation of polymethylsilsesquioxanes by the base‐catalyzed hydrolytic polycondensation of triisopropoxy(methyl)silane
Authors: Gunji Takahiro , Tanikawa Satoshi , Arimitsu Koji , Abe Yoshimoto
Published: July 2005

Base‐catalyzed hydrolytic polycondensation of trialkoxymethylsilane was investigated to synthesize polymethylsilsesquioxanes (PMSs). The reaction of trimethoxy(methyl)silane and triethoxy(methyl)silane with tetramethylammonium hydroxide, tetrabutylammonium hydroxide, and also coline gave insoluble gels. Polymethylsilsesquioxane (PMS‐IP) was obtained by the reaction of triisopropoxy(methyl)silane (MTIPS) with tetrabutylammonium hydroxide as a catalyst. PMS‐IP was composed primarily of T2 and T3 units. The percentage of T3 units and the molecular weight of PMS‐IP increased with increases in the molar ratios of catalyst and water to MTIPS and with the reaction time. PMS‐IP was soluble in organic solvents, except for methanol, and was separated by extraction with hexane and methanol into low‐ and high‐molecular‐weight fractions of Mw 2800–4000 and 7300–88,300, respectively. PMS‐IP coating films were prepared by dip coating on the organic, inorganic, and metal substrates, using the acetone–isopropyl alcohol solution of PMS‐IP. Since PMS‐IP solutions prepared with tetrabutylammonium hydroxide were hardly used because of the low content of hydroxy groups in the polymer, they showed low adhesion when compared with those solutions prepared with hydrochloric acid. The dielectric constant of the coating film prepared from the high‐molecular‐weight PMS‐IP was 2.6. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3623–3630, 2005
Comparison of sequence and structure‐based datasets for nonredundant structural data mining
Authors: Chu Carmen K. , Feng Lina L. , Wouters Merridee A.
Published: July 2005

Structural data mining studies attempt to deduce general principles of protein structure from solved structures deposited in the protein data bank (PDB). The entire database is unsuitable for such studies because it is not representative of the ensemble of protein folds. Given that novel folds continue to be unearthed, some folds are currently unrepresented in the PDB while other folds are overrepresented. Overrepresentation can easily be avoided by filtering the dataset. PDB_SELECT is a well‐used representative subset of the PDB that has been deduced by sequence comparison. Specifically, structures with sequences that exhibit a pairwise sequence identity above a threshold value are weeded from the dataset. Although length criteria for pairwise alignments have a structural basis, this automated method of pruning is essentially sequence‐based and runs into problems in the twilight zone, possibly resulting in some folds being overrepresented. The value‐added structure databases SCOP and CATH are also a potential source of a nonredundant dataset. Here we compare the sequence‐derived dataset PDB_SELECT with the structural databases SCOP (Structural Classification Of Proteins) and CATH (Class‐Architecture‐Topology‐Homology). We show that some folds remain overrepresented in the PDB_SELECT dataset while other folds are not represented at all. However, SCOP and CATH also have their own problems such as the labor‐intensiveness of the update process and the problem of determining whether all folds are equally or sufficiently distant. We discuss areas where further work is required. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Fold usage on genomes and protein fold evolution
Authors: Abeln Sanne , Deane Charlotte M.
Published: July 2005

We review fold usage on completed genomes to explore protein structure evolution. The patterns of presence or absence of folds on genomes gives us insights into the relationships between folds, the age of different folds and how we have arrived at the set of folds we see today. We examine the relationships between different measures which describe protein fold usage, such as the number of copies of a fold per genome, the number of families per fold, and the number of genomes a fold occurs on. We obtained these measures of fold usage by searching for the structural domains on 157 completed genome sequences from all three kingdoms of life. In our comparisons of these measures we found that bacteria have relatively more distinct folds on their genomes than archaea. Eukaryotes were found to have many more copies of a fold on their genomes. If we separate out the different fold classes, the alpha/beta class has relatively fewer distinct folds on large genomes, more copies of a fold on bacteria and more folds occurring in all three kingdoms simultaneously. These results possibly indicate that most alpha/beta folds originated earlier than other folds. The expected power law distribution is observed for copies of a fold per genome and we found a similar distribution for the number of families per fold. However, a more complicated distribution appears for fold occurrence across genomes, which strongly depends on fold class and kingdom. We also show that there is not a clear relationship between the three measures of fold usage. A fold which occurs on many genomes does not necessarily have many copies on each genome. Similarly, folds with many copies do not necessarily have many families or vice versa. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Modeling protein recognition of carbohydrates
Authors: Laederach Alain , Reilly Peter J.
Published: July 2005

We have a limited understanding of the details of molecular recognition of carbohydrates by proteins, which is critical to a multitude of biological processes. Furthermore, carbohydrate‐modifying proteins such as glycosyl hydrolases and phosphorylases are of growing importance as potential drug targets. Interactions between proteins and carbohydrates have complex thermodynamics, and in general the specific positioning of only a few hydroxyl groups determines their binding affinities. A thorough understanding of both carbohydrate and protein structures is thus essential to predict these interactions. An atomic‐level view of carbohydrate recognition through structures of carbohydrate‐active enzymes complexed with transition‐state inhibitors reveals some of the distinctive molecular features unique to protein–carbohydrate complexes. However, the inherent flexibility of carbohydrates and their often water‐mediated hydrogen bonding to proteins makes simulation of their complexes difficult. Nonetheless, recent developments such as the parameterization of specific force fields and docking scoring functions have greatly improved our ability to predict protein–carbohydrate interactions. We review protein–carbohydrate complexes having defined molecular requirements for specific carbohydrate recognition by proteins, providing an overview of the different computational techniques available to model them. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Large‐scale prediction of function shift in protein families with a focus on enzymatic function
Authors: Abhiman Saraswathi , Sonnhammer Erik L.L.
Published: July 2005

Protein function shift can be predicted from sequence comparisons, either using positive selection signals or evolutionary rate estimation. None of the methods have been validated on large datasets, however. Here we investigate existing and novel methods for protein function shift prediction, and benchmark the accuracy against a large dataset of proteins with known enzymatic functions. Function change was predicted between subfamilies by identifying two kinds of sites in a multiple sequence alignment: Conservation‐Shifting Sites (CSS), which are conserved in two subfamilies using two different amino acid types, and Rate‐Shifting Sites (RSS), which have different evolutionary rates in two subfamilies. CSS were predicted by a new entropy‐based method, and RSS using the Rate‐Shift program. In principle, the more CSS and RSS between two subfamilies, the more likely a function shift between them. A test dataset was built by extracting subfamilies from Pfam with different EC numbers that belong to the same domain family. Subfamilies were generated automatically using a phylogenetic tree‐based program, BETE. The dataset comprised 997 subfamily pairs with four or more members per subfamily. We observed a significant increase in CSS and RSS for subfamily comparisons with different EC numbers compared to cases with same EC numbers. The discrimination was better using RSS than CSS, and was more pronounced for larger families. Combining RSS and CSS by discriminant analysis improved classification accuracy to 71%. The method was applied to the Pfam database and the results are available athttp://FunShift.cgb.ki.se. A closer examination of some superfamily comparisons showed that single EC numbers sometimes embody distinct functional classes. Hence, the measured accuracy of function shift is underestimated. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Gram‐Scale Synthesis of Soluble, Near‐Monodisperse Gold Nanorods and Other Anisotropic Nanoparticles
Authors: Jana Nikhil R.
Published: July 2005

An aqueous surfactant‐based colloidal chemical method is reported for the synthesis of anisotropic noble‐metal nanoparticles on the milligram to multigram scale. Fine control of the nucleation‐growth kinetics and rodlike micelle‐induced breaking of symmetry at the early stage of particle growth are responsible for high‐quality anisotropic nanoparticles. Near‐monodisperse gold and silver nanorods, spheroids, nanowires, platelets, or cubes of 4–50 nm dimension and controllable aspect ratio can be prepared. The method may also be extended to semiconductor systems.
Unconventional Gallium Oxide Nanowires
Authors: Zhan Jinhua , Bando Yoshio , Hu Junqing , Xu Fangfang , Golberg Dmitri
Published: July 2005

Zigzag and helical β‐Ga2O3 one‐dimensional nanostructures were produced by thermal evaporation of gallium oxide in the presence of gallium nitride. High‐resolution TEM analysis indicates that each individual zigzag nanostructure has a periodic arrangement of three distinct blocks: two structurally perfect blocks mirrored with respect to each other on the (002) plane, and one stacking‐fault‐rich block sandwiched between them. In a zigzag nanostructure, the growth orientation of a β‐Ga2O3 crystal changes alternately in three blocks. The zigzag nanostructure as a whole has the [001] axial direction. In addition to zigzag nanostructures, single‐crystalline helical nanowires were also obtained.
Stochastic Ordering Of the Latent Trait by the Sum Score Under Various Polytomous IRT Models
Authors: van der Ark L. Andries
Published: July 2005

The sum score is often used to order respondents on the latent trait measured by the test. Therefore, it is desirable that under the chosen model the sum score stochastically orders the latent trait. It is known that unlike dichotomous item response theory (IRT) models, most polytomous IRT models do not imply stochastic ordering. It is unknown, however, (1) whether stochastic ordering is often or rarely violated and (2) whether violations yield a serious problem for practical data analysis. These are the central issues of this paper. First, some unanswered questions that pertain to polytomous IRT models implying stochastic ordering were investigated. Second, simulation studies were conducted to evaluate stochastic ordering in practical situations. It was found that for most polytomous IRT models that do not imply stochastic ordering, the sum score can be used safely to order respondents on the latent trait.
Towards a model of suicidal ideation for Hong Kong Chinese adolescents☆
Authors: Sun Rachel C.F. , Hui Eadaoin K.P. , Watkins David
Published: July 2005

This study tested a model of suicidal ideation with family cohesion, expressiveness, conflicts, teacher support, teacher–student relationships and peer support as antecedents, and self‐esteem and depression as mediators. Data was collected from survey questionnaires with 433 Hong Kong Chinese adolescents. The results showed that only family cohesion, conflicts, teacher support and peer support significantly predicted self‐esteem and depression, with depression being a strong mediator of suicidal ideation. Implications of the findings for future research were discussed.
Low temperature completely rescues the function of two misfolded KATP channel disease‐mutants
Authors: Yang Ke , Fang Kun , Fromondi Laura , Chan Kim W.
Published: July 2005

The pancreatic ATP‐sensitive potassium channels comprise two subunits: SUR1 and Kir6.2. Two SUR1 mutations, A116P and V187D, reduce channel activity causing persistent hyperinsulinemic hypoglycemia of infancy. We investigated whether these mutations cause temperature sensitive misfolding. We show that the processing defect of these mutants is temperature sensitive and these two mutations disrupt the association between SUR1 and Kir6.2 by causing misfolding in SUR1 at 37 °C but can be rescued at 18 °C. Extensive electrophysiological characterization of these mutants indicated that low temperature largely, if not completely, corrects the folding defect of these two SUR1 mutants observed at 37 °C.
NMDA receptors contribute to the survival promoting effect of high potassium in cultured cerebellar granule cells
Authors: Armanino María , Gravielle María C. , Natalia Marangoni M. , Fiszman Mónica L.
Published: July 2005

The present report further analyzes the survival promoting effect of high potassium, a condition that mimics neural activity in cultured cerebellar granule cells, an excellent model to study trophic mechanisms induced by depolarization and trophic factors. We found that the survival promoting effect measured at 7 days in vitro (DIV 7) of depolarizing potassium concentrations (25 mM KCl), added at DIV2, is partially prevented by adding at DIV 2 the non‐competitive NMDA blocker MK801 (10 μM). The concentration of MK801 used blocks completely the survival promoting effect of a supramaximal effective concentration of NMDA (100 μM). The addition at DIV 2 of anti‐brain derived neurotrophic factor (anti‐BDNF) antibody, failed to modify the effect of high potassium. The present report provides evidences that in cultured cerebellar granule cells, high potassium‐induced survival promoting effect is due in part by the activation of NMDA receptors. The effect does not require the presence of BDNF.
Ret, GFRalpha‐1, GFRalpha‐2 and GFRalpha‐3 receptors in the human hippocampus and fascia dentata
Authors: Serra Maria Pina , Quartu Marina , Mascia Francesca , Manca Annalisa , Boi Marianna , Pisu M. Giuseppina , Lai Maria Letizia , Del Fiacco Marina
Published: July 2005

The immunohistochemical occurrence and localization of the receptor components of the glial cell line‐derived neurotrophic factor (GDNF) family ligands, the Ret receptor tyrosine kinase and GDNF family receptor (GFR) alpha‐1 to ‐3, is described in the human post‐mortem hippocampal formation at pre‐ and full‐term newborn, and adult age. Two different antibodies for each of the four‐receptor molecules were used. Western blot analysis indicates that the availability of GFRalpha receptor proteins may vary with age and post‐mortem delay. The immunohistochemical detectability of GFRalpha‐1, GFRalpha‐2, GFRalpha‐3 and Ret receptor molecules is shown in the rat up to 72 h post‐mortem. In the human specimens, labelled neuronal perikarya were detectable for each receptor protein at all examined ages, with prevalent localization in the pyramidal layer of the Ammon's horn and hilus and granular layer of the fascia dentata. In the adult subjects, abundant punctate‐like structures were also present. Labelled glial elements were identifiable. Comparison of the pattern of immunoreactive elements among young and adult subjects suggests that the intracellular distribution of the GDNF family ligands may vary between pre‐ and perinatal life and adult age. The results obtained suggest the involvement of the Ret and GFRalpha receptors signalling in processes subserving both the organization of this cortical region during development and the functional activity and maintenance of the mature hippocampal neurons.
Non-Infective Subcutaneous Emphysema of the Hand Secondary to a Minor Webspace Injury
Authors: LO S. J. , HUGHES J. , ARMSTRONG A.
Published: July 2005

Subcutaneous emphysema in the hand is commonly associated with infection or high-pressure injection injuries, with other non-infectious causes being reported as rarities in the literature. We describe an unusual case of minor injury to the first webspace resulting in significant subcutaneous emphysema.
Use of structural equation modeling in operations management research: Looking back and forward
Authors: Shah Rachna , Goldstein Susan Meyer
Published: July 2005

This paper reviews applications of structural equation modeling (SEM) in four major Operations Management journals (Management Science, Journal of Operations Management, Decision Sciences, and Journal of Production and Operations Management Society) and provides guidelines for improving the use of SEM in operations management (OM) research. We review 93 articles from the earliest application of SEM in these journals in 1984 through August 2003. We document and assess these published applications and identify methodological issues gleaned from the SEM literature. The implications of overlooking fundamental assumptions of SEM and ignoring serious methodological issues are presented along with guidelines for improving future applications of SEM in OM research. We find that while SEM is a valuable tool for testing and advancing OM theory, OM researchers need to pay greater attention to these highlighted issues to take full advantage of its potential.
Factor‐product markets and firm's capital structure: A literature review
Authors: Istaitieh Abdulaziz , Rodríguez‐Fernández José M.
Published: July 2005

We present an overview of the literature that links capital structure and factor‐product markets. These studies relate some elements of the modern financial theory to the stakeholder theory, industrial organization, and firms' strategic management. Three main points are highlighted. First, the relevant role of non‐financial stakeholders in capital structure design. Second, the interactions between capital structure and market structure. Third, the two‐direction effect between the firm's capital structure and its strategic behavior in product markets. Our study aims to build an index for the existing works to guide researchers for new ideas and possible advances.
Faktorielle Validität des deutschsprachigen CVLT in der neuropsychologischen Diagnostik von Gedächtnisstörungen
Authors: Bachetzky Nadine , Jahn Thomas
Published: July 2005

Zusammenfassung: Wir untersuchten die faktorielle Validität der noch unveröffentlichten deutschsprachigen Adaptation des California Verbal Learning Test (CVLT) bei 323 Patienten mit Alzheimer-Demenz, Leichter Kognitiver Störung und Depression sowie unbeeinträchtigten gesunden Probanden im Altersbereich zwischen 50 und 80 Jahren. Analog zur Mehrzahl der englischsprachigen Studien ergab eine erste Faktorenanalyse (Hauptkomponentenanalyse mit orthogonaler VARIMAX-Rotation) anhand einer Auswahl von 19 Variablen eine 5-faktorielle Struktur mit rund 65 % Varianzaufklärung. Unter Berücksichtigung von Maßen der Stichproben- bzw. Variableneignung wurden in einer zweiten Faktorenanalyse aus 20 Variablen wiederum 5 Faktoren extrahiert, die zusammengenommen rund 72 % der Gesamtvarianz erklären. Die beiden Faktorenlösungen stimmen untereinander und mit angloamerikanischen Ergebnissen soweit überein, dass die faktorielle Validität des deutschsprachigen CVLT zur neuropsychologischen Gedächtnisprüfung bei älteren Menschen als bestätigt gelten kann. Separate Analysen in den drei klinischen Teilstichproben deckten allerdings stärker divergierende Faktorenstrukturen auf, was auf krankheitsbedingt unterschiedliche Dissoziationsmuster mnestischer Teilleistungen hinweist.
Atypische Neuroleptika in der kinder- und jugendpsychiatrischen Behandlung - Indikationen außerhalb der Schizophrenie mit Anwendungshinweisen
Authors: Mehler-Wex Claudia , Rothenhöfer Silke , Warnke Andreas
Published: July 2005

Zusammenfassung: Fragestellung: Wegen ihres besonderen Rezeptorbindungsprofils beeinflussen atypische Neuroleptika neben Produktiv- auch Minussymptome günstig. Insbesondere die Affinität zum serotonergen System legt eine Wirksamkeit auch bei zwanghaften, ängstlichen oder depressiven Symptomen nahe. Im Weiteren soll der aktuelle Stand der klinischen Erfahrungen sowie die derzeitige Studienlage zu atypischen Neuroleptika und deren Einsatz bei verschiedenen Indikationen außerhalb der Schizophrenie in der Kinder- und Jugendpsychiatrie referiert werden. Methodik: Die bisherige Studienlage wurde für die Jahre 1988 bis 2004 mittels PubMed und CurrentContents ermittelt. Ergebnisse: Anwendungsbereiche für atypische Neuroleptika sind neben Erkrankungen aus dem schizophrenen Formenkreis Ticstörungen, manische und bipolare Störungen, Impulskontrollstörungen, (Auto-)Aggressivität sowie Anorexia nervosa. Problematisch sind die lückenhafte Studienlage für das Kindes- und Jugendalter mit Fehlen von Placebo-kontrollierten Doppelblindstudien bzw. offenen Studien an größeren Populationen sowie die Off-label-Anwendung. Schlussfolgerungen: Atypische Neuroleptika sind aufgrund ihrer relativ guten Verträglichkeit Teil des Therapiestandards in der Kinder- und Jugendpsychiatrie geworden. Sie erweisen sich als wirksam bei Schizophrenien, Tics, Manien und bipolaren affektiven Störungen, Impulsivität, (Auto-)Aggressivität sowie therapieresistenten Essstörungen.
Reliabilität von Aufmerksamkeits- und verbalen Gedächtnistests bei gesunden Kindern und Jugendlichen - Implikationen für die klinische Praxis
Authors: Günther Thomas , Herpertz-Dahlmann Beate , Konrad Kerstin
Published: July 2005

Zusammenfassung: Fragestellung: Die neuropsychologische Diagnostik eignet sich zur differenzierten Beschreibung von kognitiven Leistungen bei Patienten mit kinder- und jugendpsychiatrischen Erkrankungen. In dieser Arbeit werden zunächst ein kurzer theoretischer Hintergrund für die neuropsychologischen Funktionen Aufmerksamkeit und verbales Gedächtnis gegeben und ausgewählte klinische Befunde dargestellt. Des Weiteren wird ein Beispiel einer neuropsychologischen Testbatterie vorgestellt, die im Kinder- und Jugendbereich eingesetzt werden kann. Methodik: Die Retest-Reliabilität dieser Testbatterie wurde in einem Wiederholungszeitraum von 6 Wochen bei 33 gesunden Kindern untersucht. Ergebnisse: Generell konnte eine gute Reliabilität nachgewiesen werden, obwohl es zwischen einigen abhängigen Variablen Unterschiede gab. Lerneffekte aufgrund der Wiederholung wurden vornehmlich bei den jüngeren Kindern nachgewiesen. Schlussfolgerung: Die ausgewählten neuropsychologischen Tests scheinen für die klinische Anwendung geeignet zu sein, wie z. B. die Untersuchung von kognitiven Defiziten und die Evaluierung von psychopharmakologischen Behandlungen. Es ist jedoch zu beachten, dass in Abhängigkeit vom Alter die Retest-Reliabilität unterschiedlich ist.
The Posterior Contralateral Negativity as a Temporal Indicator of Visuo-Spatial Processing
Authors: Wolber M. , Wascher E.
Published: July 2005

Abstract. The temporal segmentation of the processing stream between stimulus and response is a declared aim of many EEG-studies on cognitive processing. This goal, however, can only be reached when measures of high temporal sensitivity are available that are unequivocally assigned to a particular cognitive process. The present study evaluates the peak latency of the posterior contralateral negativity (PCN) as a temporal measure of visual spatial processing. In three experiments, we show systematic variability of the PCN latency with task demands. In visual search, PCN latency varied in the same direction as response times with the number of distractors. These effects, however, were smaller than the effects observed on response times, indicating that the process underlying the PCN might contribute to but did not determine response time effects. In contrast, in attentional cueing tasks and a stimulus localization task, where stimulus detection was the primarily addressed process, PCN latency varied to the same amount as manual response times. Thus, it is suggested that the latency of the PCN provides a reliable and valid temporal measure of target localization.
Selective Attention and Error Processing in an Illusory Conjunction Task
Authors: Wijers Albertus A. , Boksem Maarten A.S.
Published: July 2005

Abstract. We recorded event-related potentials in an illusory conjunction task, in which subjects were cued on each trial to search for a particular colored letter in a subsequently presented test array, consisting of three different letters in three different colors. In a proportion of trials the target letter was present and in other trials none of the relevant features were present. In still other trials one of the features (color or letter identity) were present or both features were present but not combined in the same display element. When relevant features were present this resulted in an early posterior selection negativity (SN) and a frontal selection positivity (FSP). When a target was presented, this resulted in a FSP that was enhanced after 250 ms as compared to when both relevant features were present but not combined in the same display element. This suggests that this effect reflects an extra process of attending to both features bound to the same object. There were no differences between the ERPs in feature error and conjunction error trials, contrary to the idea that these two types of errors are due to different (perceptual and attentional) mechanisms. The P300 in conjunction error trials was much reduced relative to the P300 in correct target detection trials. A similar, error-related negativity-like component was visible in the response-locked averages in correct target detection trials, in feature error trials, and in conjunction error trials. Dipole modeling of this component resulted in a source in a deep medial-frontal location. These results suggested that this type of task induces a high level of response conflict, in which decision-related processes may play a major role.
Global Cerebral Blood Flow and Metabolism during Acute Hyperketonemia in the Awake and Anesthetized Rat
Authors: Linde Rasmus , Hasselbalch Steen G , Topp Simon , Paulson Olaf B , Madsen Peter L
Published: July 2005

In the human setting, it has been shown that acute increase in the concentration of ketone bodies by infusion of β-hydroxybutyrate increased the cerebral blood flow (CBF) without affecting the overall cerebral metabolic activity. The mechanism by which this effect of ketone bodies was mediated is not known. Alterations in several parameters may possibly explain the increase in CBF and the resetting of the relation between CBF and cerebral metabolism. To study this phenomenon further, we measured global CBF and global cerebral metabolism with the Kety–Schmidt technique in the wakeful rat before and during infusion of ketone bodies. During acute hyperketonemia (average concentration of β-hydroxybutyrate: 6 mmol/L), global CBF increased 65% from 108 to 178 mL/***100 g min and the cerebral metabolic rates for both oxygen and glucose remained constant. This resetting of the relation between CBF and cerebral metabolism could not be explained by alterations in blood pH or arterial CO2 tension. By measuring cerebral intracellular pH by 31P nuclear magnetic resonance spectroscopy, it could further be concluded that the brain pH was unchanged during acute hyperketonemia. These observations indicate that the mechanism responsible for the increase in CBF is rather a direct effect on the cerebral endothelium than via some metabolic interactions.
Ischemic Preconditioning in the Rat Brain Enhances the Repair of Endogenous Oxidative DNA Damage by Activating the Base-Excision Repair Pathway
Authors: Li Wenjin , Luo Yumin , Zhang Feng , Signore Armando P , Gobbel Glenn T , Simon Roger P , Chen Jun
Published: July 2005

The development of ischemic tolerance in the brain, whereby a brief period of sublethal ‘preconditioning’ ischemia attenuates injury from subsequent severe ischemia, may involve the activation of multiple intracellular signaling events that promote neuronal survival. In this study, the potential role of inducible DNA base-excision repair (BER), an endogenous adaptive response that prevents the detrimental effect of oxidative DNA damage, has been studied in the rat model of ischemic tolerance produced by three episodes of ischemic preconditioning (IP). This paradigm of IP, when applied 2 and 5 days before 2-h middle cerebral artery occlusion (MCAO), significantly decreased infarct volume in the frontal-parietal cortex 72 h later. Correlated with this protective effect, IP markedly attenuated the nuclear accumulations of several oxidative DNA lesions, including 8-oxodG, AP sites, and DNA strand breaks, after 2-h MCAO. Consequently, harmful DNA damage-responsive events, including NAD depletion and p53 activation, were reduced during postischemic reperfusion in preconditioned brains. The mechanism underlying the decreased DNA damage in preconditioned brain was then investigated by measuring BER activities in nuclear extracts. Betapolymerase-mediated BER activity was markedly increased after IP, and this activation occurred before (24 h) and during the course of ischemic tolerance (48 to 72 h). In similar patterns, the activities for AP site and 8-oxodG incisions were also upregulated after IP. The upregulation of BER activities after IP was likely because of increased expression of repair enzymes beta-polymerase, AP endonuclease, and OGG1. These results suggest that the activation of the BER pathway may contribute to IP-induced neuroprotection by enhancing the repair of endogenous oxidative DNA damage after ischemic injury.
Entscheidungen am Lebensende in der Intensivmedizin
Authors: Strätling M. , Schmucker P.
Published: July 2005

Diese Arbeit stellt den letzten Teil einer Serie von drei Weiterbildungsartikeln dar. Diese sollen wesentliche Grundlagen für den Umgang mit ethischen, rechtlichen und kommunikativen Problemen am Beispiel von „Entscheidungen am Lebensende” in der Intensivmedizin vermitteln.
GeoTime Information Visualization
Authors: Kapler Thomas , Wright William
Published: July 2005

Analyzing observations over time and geography is a common task, but typically requires multiple, separate tools. The objective of our research has been to develop a method to visualize, and work with, the spatial inter-connectedness of information over time and geography within a single, highly interactive three-dimensional (3-D) view. A novel visualization technique for displaying and tracking events, objects and activities within a combined temporal and geospatial display has been developed. This technique has been implemented as a demonstrable prototype called GeoTime in order to determine potential utility. Capabilities include descriptive events and relationships, association analysis, event aggregation methods and geo-located linked charting. Initial evaluations have been with military users. However, we believe the concept is applicable to a variety of government and business analysis tasks.
Caudal Fin Mercury as a Non-Lethal Predictor of Fish-Muscle Mercury
Authors: Gremillion Paul T. , Cizdziel James V. , Cody Norman R.
Published: July 2005

Environmental Context. Surveys to assess the body burden of mercury in fish to support research or contamination advisory programs typically involve capturing and killing fish and analyzing muscle tissue for mercury. Lethal sampling may not be feasible in protected waters or in studies involving threatened or endangered species. We analyzed tail fin samples of two fish species for total mercury and compared results with muscle-tissue mercury and concluded that fin-Hg can be used as a predictor of muscle-Hg. This approach enables catch and release studies for mercury in fish.
Abstract. The caudal (tail) fins from 17 walleye (Sander vitreus) and 12 northern pike (Esox lucius) from three northern Arizona lakes (Long Lake, Soldier Lake, and Upper Lake Mary) were analyzed for total-Hg by combustion–atomic absorption spectrometry. Results indicate that the fin contains measurable Hg that correlates with muscle-Hg concentrations. As the body burden of Hg increased, the concentration in the fin increased relative to the muscle. Mercury concentrations also increased with fish length and weight, although the relationship was lake- and species-dependent. Fish from Soldier Lake had the most efficient uptake of Hg, likely due to the trophic structure of the lake or the condition of the fish, but possibly due to an acute source of Hg. Overall, this study demonstrates that caudal fin clippings can be used as a non-lethal predictor of muscle-Hg concentrations, which can reduce the number of fish killed in routine monitoring programs.
Firework Emissions for Satellite Validation?
Authors: Williams Jonathan , Drewnick Frank , Hings Silke S. , Curtius Joachim , Eerdekens Gunter , Klüpfel Thomas , Wagner Thomas
Published: July 2005

Environmental Context. Satellite-based instruments for monitoring the Earth’s atmosphere observe the distribution of many gases and particles of interest. Many common sources of atmospheric gases and particles, such as fires, are geographically widespread and occur over a moderately long period. In contrast, fireworks pollute only a local area and for a brief period, and thus act as an ideal test of satellite instruments.
Occurrence and Speciation of Arsenic in Common Australian Coastal Polychaete Species
Authors: Waring Joel , Maher William , Foster Simon , Krikowa Frank
Published: July 2005

Environmental Context. In well-oxygenated water and sediments, nearly all arsenic is present as arsenate (AsO43−). As arsenate is a phosphate (PO43−) analogue, organisms living in arsenate-rich environments must acquire the nutrient phosphorus yet avoid arsenic toxicity. Organisms take in and transform arsenic compounds by many means. Three major modes of arsenic biotransformation have been found to occur in the environment—redox transformation between arsenate and arsenite (AsO2−), the reduction and methylation of arsenic, and the biosynthesis of organoarsenic compounds such as arsenobetaine. These biotransformations lead to biogeochemical cycling of arsenic compounds and bioconcentration of arsenic in aquatic organisms and thence into the food web.
Abstract. The paper reports the whole-tissue total arsenic concentrations and water-soluble arsenic species in eight common coastal Australian polychaete species.
Laboratory experiments showed the period of depuration did not significantly alter the whole-tissue total arsenic concentrations in the two estuarine polychaete species tested.
Significant differences were found between the whole-tissue total arsenic concentrations of the eight polychaete species (mean arsenic concentrations ranged from 18 to 101 µg g−1 dry mass). Total arsenic concentrations in polychaete species, grouped on the basis of a combination of their feeding guild and habitat type, were also significantly different with a significant interaction between these factors indicating that both factors simultaneously influence arsenic concentration in polychaetes.
A large number of polychaete species contained similar arsenic species with high proportions of arsenobetaine (AB; 57–88%) and relatively low proportions of As3+, As5+, methyarsonic acid, dimethylarsinic acid, arsenocholine, trimethylarsoniopropionate, and tetramethylarsonium ion (not detected to 12%). All polychaete species contained arsenoribosides (5–30%). This study identified two Australian polychaete species with particularly unusual whole-tissue water-soluble arsenic species proportions: Australonuphis parateres contained a very high proportion of trimethylarsoniopropionate (~33%), while Notomastus estuarius had a very low proportion of arsenobetaine (9%) and high proportions of As3+ (~30%), As5+ (~8%), arsenoribosides (30%), and an unknown anionic arsenic species (~4%).
Most polychaetes accumulate arsenobetaine, except deposit feeders inhabiting estuarine mud habitats. Thus most polychaetes, which are prey for higher organisms, are a source of arsenobetaine in benthic food webs. Deposit feeders inhabiting estuarine muddy substrates contain appreciable quantities of inorganic arsenic and arsenoribosides that may be metabolized to different end products in higher organisms.
Estimating the total genetic diversity of a spatial field population from a sample and implications of its dependence on habitat area
Authors: Rauch Erik M. , Bar-Yam Yaneer
Published: July 2005

The total genetic diversity of a species is a key factor in its persistence and conservation. Because realistic sample sizes are far smaller than the total population, it is impractical to exhaustively characterize diversity of most populations. Here, we demonstrate the possibility of calculating the genetic diversity of a spatial population from a sample using genealogical models. We trace the history of a population by simulating the locations of the ancestors of a particular sample of the population backwards in time. We use this method to estimate the genetic diversity of the global population of
Pseudomonas
bacteria. The same results are obtained whether using a global sample or a subsample restricted to a particular geographic region (California). The results are also validated by comparing additional predictions of the model to the data. Furthermore, we use these results to show that the level of genetic diversity in a population depends strongly on the size of its habitat, much more strongly than does biodiversity as measured by the number of species. The strong dependence of diversity on habitat area has significant implications for conservation strategies.
Stochastic model for Soj relocation dynamics in
Bacillus subtilis
Authors: Doubrovinski Konstantin , Howard Martin
Published: July 2005

The
Bacillus subtilis
Spo0J/Soj proteins, implicated in chromosome segregation and transcriptional regulation, show striking dynamics: Soj undergoes irregular relocations from pole to pole or nucleoid to nucleoid. Here, we report on a mathematical model of the Soj dynamics. Our model, which is closely based on the available experimental data, readily generates dynamic Soj relocations. We show that the irregularity of the relocations may be due to the stochastic nature of the underlying Spo0J/Soj interactions and diffusion. We propose explanations for the behavior of several Spo0J/Soj mutants, including the “freezing” of the Soj dynamics observed in filamentous cells. Our approach underlines the importance of incorporating stochastic effects when modeling spatiotemporal protein dynamics inside cells.
Operational effectiveness of suicide-bomber-detector schemes: A best-case analysis
Authors: Kaplan Edward H. , Kress Moshe
Published: July 2005

Standoff explosives-detection technologies allow, in principle, for the detection of pedestrian suicide bombers, although such sensors are not yet sufficiently affordable and reliable to justify widespread deployment. What if they were? Assuming the availability of cheap, perfectly sensitive and specific suicide-bomber-sensing devices, we analyze the operational effectiveness of sensor-based detector schemes in reducing casualties from random suicide-bombing attacks. We model the number of casualties resulting from pedestrian suicide bombings absent intervention, the reduction in casualties from alternative interventions, given timely detection of a suicide-bombing attack, and the probability of timely detection under best-case assumptions governing the performance of suicide-bomber-detector schemes in two different urban settings. Even under such optimistic assumptions, we find that the widespread deployment of suicide-bomber detectors will not reliably result in meaningful casualty reductions. Relaxing the best-case assumptions only makes matters worse. Investment in intelligence-gathering to prevent suicide bombers before they attack seems a wiser strategy than relying on sensor-based suicide-bomber-detector schemes.
An integrated functional genomics and metabolomics approach for defining poor prognosis in human neuroendocrine cancers
Authors: Ippolito Joseph E. , Xu Jian , Jain Sanjay , Moulder Krista , Mennerick Steven , Crowley Jan R. , Townsend R. Reid , Gordon Jeffrey I.
Published: July 2005

Human neuroendocrine (NE) cancers range from relatively indolent to highly aggressive. In this study, we combine functional genomics with metabolomics to identify features of NE cancers associated with a poor outcome. Analysis of GeneChip datasets of primary prostate tumors, as well as lymph node and liver metastases from transgenic mice with a NE cell cancer, plus derived NE cell lines yielded a signature of 446 genes whose expression is enriched in neoplastic mouse prostatic NE cells. This signature was used for
in silico
metabolic reconstructions of NE cell metabolism, directed liquid chromatography/tandem MS analysis of metabolites in prostatic NE tumors and cell lines, and analysis of GeneChip datasets of human NE tumors with good or poor prognoses. The results indicate that a distinguishing feature of poor-prognosis NE tumors is a glutamic acid decarboxylase-independent pathway for production of GABA and a pathway for production of imidazole-4-acetate that involves dopa decarboxylase and a membrane-associated amine oxidase, amiloride-binding protein 1. Electrophysiological studies disclosed that imidazole-4-acetate can bind and activate GABA
A
receptors expressed by transformed NE cells, thus providing a previously uncharacterized paradigm for NE tumor cell signaling. Transcriptional, metabolic, and electrophysiologic features of transformed mouse NE cells are also evident in neural progenitor cells.