bluuebunny/crossref_metadata_2025 huggingface dataset:
Centromere-Proximal Crossovers Are Associated With Precocious Separation of Sister Chromatids During Meiosis inSaccharomyces cerevisiae
Authors: Rockmill Beth , Voelkel-Meiman Karen , Roeder G Shirleen
Published: October 2006

In most organisms, meiotic chromosome segregation is dependent on crossovers (COs), which enable pairs of homologous chromosomes to segregate to opposite poles at meiosis I. In mammals, the majority of meiotic chromosome segregation errors result from a lack of COs between homologs. Observations in Homo sapiens and Drosophila melanogaster have revealed a second class of exceptional events in which a CO occurred near the centromere of the missegregated chromosome. We show that in wild-type strains of Saccharomyces cerevisiae, most spore inviability is due to precocious separation of sister chromatids (PSSC) and that PSSC is often associated with centromere-proximal crossing over. COs, as opposed to nonreciprocal recombination events (NCOs), are preferentially associated with missegregation. Strains mutant for the RecQ homolog, SGS1, display reduced spore viability and increased crossing over. Much of the spore inviability in sgs1 results from PSSC, and these events are often associated with centromere-proximal COs, just as in wild type. When crossing over in sgs1 is reduced by the introduction of a nonnull allele of SPO11, spore viability is improved, suggesting that the increased PSSC is due to increased crossing over. We present a model for PSSC in which a centromere-proximal CO promotes local loss of sister-chromatid cohesion.
Substitution Mapping in Dahl Rats Identifies Two Distinct Blood Pressure Quantitative Trait Loci Within 1.12- and 1.25-Mb Intervals on Chromosome 3
Authors: Lee Soon Jin , Liu Jun , Westcott Allison M , Vieth Joshua A , DeRaedt Sarah J , Yang Siming , Joe Bina , Cicila George T
Published: October 2006

Substitution mapping was used to refine the localization of blood pressure (BP) quantitative trait loci (QTL) within the congenic region of S.R-Edn3 rats located at the q terminus of rat chromosome 3 (RNO3). An F2(S × S.R-Edn3) population (n = 173) was screened to identify rats having crossovers within the congenic region of RNO3 and six congenic substrains were developed that carry shorter segments of R-rat-derived RNO3. Five of the six congenic substrains had significantly lower BP compared to the parental S rat. The lack of BP lowering effect demonstrated by the S.R(ET3 × 5) substrain and the BP lowering effect retained by the S.R(ET3 × 2) substrain together define the RNO3 BP QTL-containing region as ∼4.64 Mb. Two nonoverlapping substrains, S.R(ET3 × 1) and S.R(ET3 × 6), had significantly lower BP compared to the S strain, indicating the presence of two distinct BP QTL in the RNO3 q terminus. The RNO3 q terminus was fine mapped with newly developed polymorphic markers to characterize the extent of the congenic regions. The two RNO3 BP QTL regions were thus defined as within intervals of 0.05–1.12 and 0.72–1.25 Mb, respectively. Also important was our difficulty in fine mapping and marker placement in this portion of the rat genome (and thus candidate gene identification) using the available genomic data, including the rat genome sequence.
Testing Chromosomal Phylogenies and Inversion Breakpoint Reuse in Drosophila
Authors: González Josefa , Casals Ferran , Ruiz Alfredo
Published: October 2006

A combination of cytogenetic and bioinformatic procedures was used to test the chromosomal phylogeny relating Drosophila buzzatii with D. repleta. Chromosomes X and 2, harboring most of the inversions fixed between these two species, were analyzed. First, chromosomal segments conserved during the divergence of the two species were identified by comparative in situ hybridization to the D. repleta chromosomes of 180 BAC clones from a BAC-based physical map of the D. buzzatii genome. These conserved segments were precisely delimited with the aid of clones containing inversion breakpoints. Then GRIMM software was used to estimate the minimum number of rearrangements necessary to transform one genome into the other and identify all possible rearrangement scenarios. Finally, the most plausible inversion trajectory was tested by hybridizing 12 breakpoint-bearing BAC clones to the chromosomes of seven other species in the repleta group. The results show that chromosomes X and 2 of D. buzzatii and D. repleta differ by 12 paracentric inversions. Nine of them are fixed in chromosome 2 and entail two breakpoint reuses. Our results also show that the cytological relationship between D. repleta and D. mercatorum is closer than that between D. repleta and D. peninsularis, and we propose that the phylogenetic relationships in this lineage of the repleta group be reconsidered. We also estimated the rate of rearrangement between D. repleta and D. buzzatii and conclude that rates within the genus Drosophila vary substantially between lineages, even within a single species group.
The Transposable Element Landscape of the Model LegumeLotus japonicus
Authors: Holligan Dawn , Zhang Xiaoyu , Jiang Ning , Pritham Ellen J , Wessler Susan R
Published: October 2006

The largest component of plant and animal genomes characterized to date is transposable elements (TEs). The availability of a significant amount of Lotus japonicus genome sequence has permitted for the first time a comprehensive study of the TE landscape in a legume species. Here we report the results of a combined computer-assisted and experimental analysis of the TEs in the 32.4 Mb of finished TAC clones. While computer-assisted analysis facilitated a determination of TE abundance and diversity, the availability of complete TAC sequences permitted identification of full-length TEs, which facilitated the design of tools for genomewide experimental analysis. In addition to containing all TE types found in previously characterized plant genomes, the TE component of L. japonicus contained several surprises. First, it is the second species (after Oryza sativa) found to be rich in Pack-MULEs, with >1000 elements that have captured and amplified gene fragments. In addition, we have identified what appears to be a legume-specific MULE family that was previously identified only in fungal species. Finally, the L. japonicus genome contains many hundreds, perhaps thousands of Sireviruses: Ty1/copia-like elements with an extra ORF. Significantly, several of the L. japonicus Sireviruses have recently amplified and may still be actively transposing.
Phylogenetic Analysis of Fungal Centromere H3 Proteins
Authors: Baker Richard E , Rogers Kelly
Published: October 2006

Centromere H3 proteins (CenH3's) are variants of histone H3 specialized for packaging centromere DNA. Unlike canonical H3, which is among the most conserved of eukaryotic proteins, CenH3's are rapidly evolving, raising questions about orthology and conservation of function across species. To gain insight on CenH3 evolution and function, a phylogenetic analysis was undertaken on CenH3 proteins drawn from a single, ancient lineage, the Fungi. Using maximum-likelihood methods, a credible phylogeny was derived for the conserved histone fold domain (HFD) of 25 fungal CenH3's. The collection consisted mostly of hemiascomycetous yeasts, but also included basidiomycetes, euascomycetes, and an archaeascomycete. The HFD phylogeny closely recapitulated known evolutionary relationships between the species, supporting CenH3 orthology. The fungal CenH3's lacked significant homology in their N termini except for those of the Saccharomyces/Kluyveromyces clade that all contained a region homologous to the essential N-terminal domain found in Saccharomyces cerevisiae Cse4. The ability of several heterologous CenH3's to function in S. cerevisiae was tested and found to correlate with evolutionary distance. Domain swapping between S. cerevisiae Cse4 and the noncomplementing Pichia angusta ortholog showed that species specificity could not be explained by the presence or absence of any recognized secondary structural element of the HFD.
Functional Characterization of Drosophila Translin and Trax
Authors: Claußen Maike , Koch Rafael , Jin Zhao-Yang , Suter Beat
Published: October 2006

The vertebrate RNA and ssDNA-binding protein Translin has been suggested to function in a variety of cellular processes, including DNA damage response, RNA transport, and translational control. The Translin-associated factor X (Trax) interacts with Translin, and Trax protein stability depends on the presence of Translin. To determine the function of the Drosophila Translin and Trax, we generated a translin null mutant and isolated a trax nonsense mutation. translin and trax single and double mutants are viable, fertile, and phenotypically normal. Meiotic recombination rates and chromosome segregation are also not affected in translin and trax mutants. In addition, we found no evidence for an increased sensitivity for DNA double-strand damage in embryos and developing larvae. Together with the lack of evidence for their involvement in DNA double-strand break checkpoints, this argues against a critical role for Translin and Trax in sensing or repairing such DNA damage. However, Drosophila translin is essential for stabilizing the Translin interaction partner Trax, a function that is surprisingly conserved throughout evolution. Conversely, trax is not essential for Translin stability as trax mutants exhibit normal levels of Translin protein.
Evolution of Amino-Acid Sequences and Codon Usage on the Drosophila miranda Neo-Sex Chromosomes
Authors: Bartolomé Carolina , Charlesworth Brian
Published: October 2006

We have studied patterns of DNA sequence variation and evolution for 22 genes located on the neo-X and neo-Y chromosomes of Drosophila miranda. As found previously, nucleotide site diversity is greatly reduced on the neo-Y chromosome, with a severely distorted frequency spectrum. There is also an accelerated rate of amino-acid sequence evolution on the neo-Y chromosome. Comparisons of nonsynonymous and silent variation and divergence suggest that amino-acid sequences on the neo-X chromosome are subject to purifying selection, whereas this is much weaker on the neo-Y. The same applies to synonymous variants affecting codon usage. There is also an indication of a recent relaxation of selection on synonymous mutations for genes on other chromosomes. Genes that are weakly expressed on the neo-Y chromosome appear to have a faster rate of accumulation of both nonsynonymous and unpreferred synonymous mutations than genes with high levels of expression, although the rate of accumulation when both types of mutation are pooled is higher for the neo-Y chromosome than for the neo-X chromosome even for highly expressed genes.
Cis-regulatory Evolution of Chalcone-Synthase Expression in the Genus Arabidopsis
Authors: de Meaux Juliette , Pop A , Mitchell-Olds T
Published: October 2006

The contribution of cis-regulation to adaptive evolutionary change is believed to be essential, yet little is known about the evolutionary rules that govern regulatory sequences. Here, we characterize the short-term evolutionary dynamics of a cis-regulatory region within and among two closely related species, A. lyrata and A. halleri, and compare our findings to A. thaliana. We focused on the cis-regulatory region of chalcone synthase (CHS), a key enzyme involved in the synthesis of plant secondary metabolites. We observed patterns of nucleotide diversity that differ among species but do not depart from neutral expectations. Using intra- and interspecific F1 progeny, we have evaluated functional cis-regulatory variation in response to light and herbivory, environmental cues, which are known to induce CHS expression. We find that substantial cis-regulatory variation segregates within and among populations as well as between species, some of which results from interspecific genetic introgression. We further demonstrate that, in A. thaliana, CHS cis-regulation in response to herbivory is greater than in A. lyrata or A. halleri. Our work indicates that the evolutionary dynamics of a cis-regulatory region is characterized by pervasive functional variation, achieved mostly by modification of response modules to one but not all environmental cues. Our study did not detect the footprint of selection on this variation.
Continuous, automated and simultaneous measurement of oxygen uptake and carbon dioxide evolution in biological systems
Authors: Govind Rakesh , Gao Chao , Lai Lie , Tabak Henry H.
Published: October 2006

Commercial respirometers are capable of continuously and automatically measuring oxygen uptake in bioreactors. A method for continuously and automatically measuring carbon dioxide evolution can be retrofitted to commercial respirometers. Continuous and automatic measurements of carbon dioxide evolution are achieved by measuring the change in electrical conductivity of barium hydroxide solution. Continuous stirring of the barium hydroxide solution was necessary to prevent the carbon dioxide absorption from controlling the oxygen uptake rate. Three separate experiments (aqueous biodegradation of phenol, soil slurry biotreatment of soil contaminated with phenol, and aqueous biodegradation of crude oil) were conducted to test the oxygen uptake and carbon dioxide evolution measurement system. The respiratory quotient, defined as the ratio of carbon dioxide evolution to oxygen uptake, is close to one until a plateau of oxygen uptake is reached, after which it is greater than one due to degradation of biomass and metabolite products. Unsteady‐state simulation of CO2 evolution in batch reactors, based on the experimental data, showed that carbon dioxide exists primarily as bicarbonate in the liquid phase. The concentration of carbon dioxide in the gas phase is small mainly due to fast reaction with the stirred barium hydroxide solution.
The Anatomy of the Sphenopalatine Artery for the Endoscopic Sinus Surgeon
Authors: Simmen Daniel B. , Raghavan Ullas , Briner Hans Rudolf , Manestar Mirjana , Groscurth Peter , Jones Nick S.
Published: October 2006

Background

This study was performed to determine the variations in the branching pattern of the sphenopalatine artery medial to the crista ethmoidalis. Seventy-seven cadaver head sides that had been sectioned sagittally in the midline with their septum removed were used after injecting pink latex to highlight the arterial vessels.

Methods

The mucosa from the middle meatus from the level of the basal lamella was removed until the artery and its branches were seen and then was examined under the microscope to identify the position of the arterial branches.

Results

The sphenopalatine artery and its branches were identified in 75 specimens. Of these 75 specimens, 73 (97%) had 2 or more branches medial to the crista ethmoidalis, 49 (67%) had 3 or more branches, 26 (35%) had 4 or more branches, and 1 specimen had 10 branches. In two specimens the artery presented as a single trunk.

Conclusion

The sphenopalatine artery normally starts to branch lateral to the crista ethmoidalis and these branches vary widely. It is important that the surgeon who undertakes ligation or cautery of the artery is aware of these variations, otherwise they may overlook some of the branches. With an endoscopic approach, removal of the crista ethmoidalis helps visualize these branches.
Light and Electron Microscopic Study of Primary Atrophic Rhinitis Mucosa
Authors: Sayed Ramadan Hashem , Abou-Elhamd Kamal-Eldin Ahmed , Makhlouf Madeha M. M.
Published: October 2006

Background

This study examined the light and the electron microscopic changes in the mucosa of primary atrophic rhinitis and compared them with the normal nasal mucosa to establish the changes in the surfactant system. A prospective original study was performed.

Methods

Twenty cases of primary atrophic rhinitis were randomly selected in the outpatient clinic of Sohag University Ear, Nose, and Throat Department. Ten volunteers with no history of chronic nasal disease and with normal rhinopharyngeal picture were selected as control cases. A small punch biopsy was performed with a small forceps under local anesthesia from the medial edge of the inferior turbinate. After histological laboratory preparations, semithin sections (0.5–1 μm) were prepared by using an LKB ultramicrotome. The sections were stained by toluidine blue, examined by light microscope, and photographed. Ultrathin sections (500–800) from selected areas of the trimmed blocks were made and collected on copper grids. The ultrathin sections were then contrasted in uranyl acetate for 10 minutes and examined by electron microscope Jeol JEM-1010.

Results

Light microscopy of primary atrophic epithelium revealed typical nonkeratinized stratified squamous epithelium to keratinized squamous epithelium with a thin layer of keratin on the surface. Well-developed desmosomes appeared between the epithelial cells. In the lamina propria, no submucosal glands could be seen. Electron microscopy of it revealed that the stratification of the epithelium increased. Sloughing of the superficial cells was observed in some regions of the proliferating epithelium. Epithelial penetration with neutrophils (mainly) and lymphocytes (some) could be seen. No numerous multilamellar bodies (MLBs) could be detected in these cases. An increased amount of collagenous fibers was observed in the basement membrane.

Conclusion

In primary atrophic rhinitis, the epithelial cells revealed that desmosomes are characteristic of the metaplastic squamous epithelium and had no MLB in their cytoplasm, and cells in which occasional MLBs had been established showed interdigitations between them and the surrounding cells, suggesting an association between the surfactant deficiency and the development of desmosomes.
Effect of Cooling on Electrical Field Stimulation and Norepinephrine-Induced Contraction in Isolated Hypertrophic Human Nasal Mucosa
Authors: Chu Yueng-Hsiang , Wu Chin-Chen , Wang Hsing-Won
Published: October 2006

Background

Exposure to cold causes cutaneous vasoconstriction to reduce body heat loss, while the nasal cavity warms up the inspired cold air. This suggests cooling might evoke a different response in nasal mucosa blood vessels than in cutaneous blood vessels. Thus, the aim of this study was to evaluate the effect of cooling (to 24°C) on the vascular response of isolated nasal mucosa.

Methods

An in vitro isometric contraction of nasal mucosa excised from patients suffered from chronic nasal congestion was continuously recorded. Either electrical field stimulation (EFS) or exogenous norepinephrine (NE) was applied to the turbinate mucosa strip at 37 and 24°C, and the influence of cooling (to 24°C) was evaluated.

Results

EFS (1, 2, 4, and 8 Hz) produced frequency-dependent contractions at 37 and 24°C. Cooling did not alter the magnitude but significantly prolonged the duration of EFS-induced contraction. Exogenous NE (10-8to 10-4M) produced concentration-dependent contractions at 37 and 24°C. Cooling significantly enhanced the contractile responses evoked by NE between 3 × 10-6and 1 × 10-4M.

Conclusion

Cooling (to 24°C) prolonged the EFS-induced and enhanced NE (3 × 10-6to 1 × 10-4M)-induced contraction of isolated human nasal mucosa.
Associative Practices in the Management of Complexity
Authors: Verebes Tom
Published: October 2006

Tom Verebes, a co‐director of the Architectural Association's Design Research Laboratory (DRL), writes about the programme's recent research in generative and parametric‐based software, as well as the actualisation of these innovations through automated fabrication technologies. One example is the DRL's recent initiative to collaborate with Gehry Technologies as a means of using an experimental academic environment to test professional design software applications currently in development. As Verebes shows, this integration extends into his own collaborative design office, ocean D, one of the surviving branches of the original OCEAN network that emerged in the early 1990s (discussed elsewhere in the issue by Michael Hensel). For Verebes, as for Brett Steele (also featured in this publication), academic research serves as a laboratory for the production of new practices. Copyright © 2006 John Wiley & Sons, Ltd.
Designing Commonspaces: Riffing with Michael Hardt on the Multitude and Collective Intelligence
Authors: Hight Christopher
Published: October 2006

Michael Hardt has made an indispensable contribution to current understanding of the impact of globalisation on social, economic and political practice, especially in his two books, Empire and Multitude: War and Democracy in the Age of Empire. In order to engage Hardt with many of the projects and ideas raised in this issue, guest‐editors Christopher Hight and Chris Perry invited him to participate in a blog. The blog format enabled the resulting exchange between Christopher Hight and Hardt to be an open platform relating concepts like ‘empire’ and ‘multitude’ to contemporary design practice, and even raised challenges implicit in Hardt's own work. It also provided a productive alternative to the expropriation of a theorist's writings to legitimatise a particular design approach or methodology. Copyright © 2006 John Wiley & Sons, Ltd.
Clouds make nerds look good: field evidence of the impact of incidental factors on decision making
Authors: Simonsohn Uri
Published: October 2006

Abundant experimental research has documented that incidental primes and emotions are capable of influencing people's judgments and choices. This paper examines whether the influence of such incidental factors is large enough to be observable in the field, by analyzing 682 actual university admission decisions. As predicted, applicants' academic attributes are weighted more heavily on cloudier days and non‐academic attributes on sunnier days. The documented effects are of both statistical and practical significance: changes in cloud cover can increase a candidate's predicted probability of admission by an average of up to 11.9%. These results also shed light on the causes behind the long demonstrated unreliability of experts making repeated judgments from the same data. Copyright © 2006 John Wiley & Sons, Ltd.
Bone morphogenetic protein‐4 expression in the adult rat brain
Authors: Mikawa Sumiko , Wang Cong , Sato Kohji
Published: October 2006

Bone morphogenetic protein‐4 (BMP4) is a member of the transforming growth factor‐β (TGF‐β) superfamily and plays important roles in multiple biological events. Although BMP4 expression has been well described in the early development of the central nervous system (CNS), little information is available on its expression in the adult CNS. Therefore, we investigated BMP4 expression in the adult rat CNS by using immunohistochemistry. BMP4 is intensely expressed in most neurons and their dendrites. In addition, intense BMP4 expression was also observed in the neuropil of the gray matters where high plasticity is reported, such as the molecular layer of the cerebellum and the superficial layer of the superior colliculus. Furthermore, we found that astrocytes also express BMP4 protein. These data indicate that BMP4 is more widely expressed throughout the adult CNS than previously reported, and its continued abundant expression in the adult brain strongly supports the idea that BMP4 plays pivotal roles also in the adult brain. J. Comp. Neurol. 499:613–625, 2006. © 2006 Wiley‐Liss, Inc.
The economic cost of teen drinking: late graduation and lowered earnings
Authors: Renna Francesco
Published: October 2006

This paper analyzes the effect that binge drinking has on the probability of graduating on time from high school and on future earnings. The analysis is conducted on students in their senior year of high school using data from the National Longitudinal Survey of Youth 1979. Importantly, the usual instruments used to correct for the endogeneity of the drinking variable are found to be robust only for women. This paper finds that heavy drinking decreases the probability of graduating on time. Binge drinking does not have a direct impact on adults' labor earnings, but graduating late results in lower labor income. Because of a late graduation, young men who binge in high school will face an earnings penalty of 1.5–1.84 percentage points. Women also face a penalty, but this seems mostly due to the fact that women who graduate late work in industries and occupations that pay less. Copyright © 2006 John Wiley & Sons, Ltd.
Child care before 6 months of age: a qualitative study of mothers' decisions and feelings about employment and non‐maternal care
Authors: Leach Penelope , Barnes Jacqueline , Nichols Michelle , Goldin Jon , Stein Alan , Sylva Kathy , Malmberg Lars‐Erik ,   the FCCC team
Published: October 2006

Employment of women while their children are infants has increased in the UK in the last decade. This study of 57 employed mothers of infants less than seven months old examined their retrospective reports of planning child care and their contemporaneous feelings about the child care they were using, based on qualitative interviews. Issues addressed included mothers' reasons for returning to employment at that time, their theoretical preferences among a range of child care types and providers and the process of making actual choices, including the range and types of advice received and the involvement of fathers. Mothers were also encouraged to discuss their feelings about how child care was working out once the infant was settled. Continuing concerns expressed by mothers included the importance of open communication with caregivers, their desire to keep control over infants' daily lives and upbringing, worries about infants' safety and concerns about the levels of cognitive stimulation they received. Copyright © 2006 John Wiley & Sons, Ltd.
4‐[18F]fluorophenyl ureas via carbamate‐4‐nitrophenyl esters and 4‐[18F]fluoroaniline
Authors: Olma Sebastian , Ermert Johannes , Coenen Heinz H.
Published: October 2006

Four different no carrier added (n.c.a.) 4‐[18F]fluorophenylurea derivatives are synthesized as model compounds via two alternative routes. In both cases carbamate‐4‐nitrophenylesters are used as intermediates. Either n.c.a. 4‐[18F]fluoroaniline reacts with carbamates of several amines, or the carbamate of n.c.a. 4‐[18F]fluoroaniline is formed at first and an amine is added subsequently to yield the urea derivative. The choice of the appropriate way of reaction depends on the possibilities of precursor synthesis.

The radiochemical yields reach up to 80% after 50 min of synthesis time while no radiochemical by‐products can be determined. These high yields were possible due to an optimized preparation of n.c.a. 4‐[18F]fluoroaniline with a radiochemical yield of up to 90%. From the various ways of its radiosynthesis, the substitution with n.c.a. [18F]fluoride on dinitrobenzene is chosen, using phosphorous acid and palladium black for reduction of the second nitro group. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis of isotopomers of dopamine labeled with deuterium or tritium
Authors: Pająk M. , Kańska M.
Published: October 2006

The synthesis of four isotopomers of dopamine labeled with deuterium or tritium is reported. The ring labeled [2′,5′,6′‐2H3]‐, and [2′,5′,6′‐3H3]‐dopamine were obtained using acid catalyzed isotopic exchange between dopamine and heavy or tritiated water respectively. Two selectively labeled isotopomers, i.e. [1R‐2H]‐, and [1R‐3H]‐dopamine were synthesized by enzymatic decarboxylation of L‐DOPA using the enzyme tyrosine decarboxylase (EC 4.1.1.25) from Streptococcus faecalis. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis and bio evaluation of a new fatty acid derivative labelled with technetium‐99m
Authors: Mathur Anupam , Mallia Madhava B. , Subramanian Suresh , Banerjee Sharmila , Kothari K. , Sarma H. D. , Venkatesh Meera
Published: October 2006

123I‐iodophenylpentadecanoic acid (IPPA) and 123I‐beta‐methyliodophenylpentadecanoic acid (BMIPP) are radiolabelled fatty acid derivatives used for assessment of myocardial viability. Because of limited accessibility of 123I in the clinical scenario, a 99m‐technetium‐based agent would be more advantageous. In this context, a xanthate derivative of 15‐hydroxypentadecanoic acid (HPDA) was synthesized for radiolabelling with [99mTcN]2+ intermediate.

Direct reaction of the HPDA with carbon disulphide in presence of crushed sodium hydroxide in dry tetrahydrofuran resulted in moderate yield of the desired xanthate product. The prepared ligand was radiolabelled with [99mTcN]2+ intermediate and the resultant complex was characterized by paper electrophoresis and HPLC. The labelled preparation was assessed for its myocardial extraction and retention characteristics using Swiss mice model.

The HPDA xanthate derivative was obtained in a low yield of ∼30%. Labelling via the [99mTcN]2+intermediate gave more than 95% complexation. During in vivo studies with the [TcN]2+ labelled complex maximum heart uptake observed was 3.10%ID/g at 5 min p.i., which cleared out rapidly, with retention of 0.79%ID/g of the activity at 60 min p.i.

The 99mTcN‐HPDA xanthate derivative showed some uptake in the heart but rapid wash out and substantial uptake in the background organs (blood, liver and lungs) led to unfavourable critical ratios at all the time points of study. Copyright © 2006 John Wiley & Sons, Ltd.
Correlation between dynamic susceptibility contrast perfusion MRI and methionine metabolism in brain gliomas: Preliminary results
Authors: Sadeghi Niloufar , Salmon Isabelle , Tang Bich Ngoc Thanh , Denolin Vincent , Levivier Marc , Wikler David , Rorive Sandrine , Balériaux Danielle , Metens Thierry , Goldman Serge
Published: October 2006

Purpose

To evaluate in brain gliomas the relationship between tumor vascularity measured by MR‐based maximum regional cerebral blood volume (rCBV) and tumor amino‐acid metabolism based on maximum carbon‐11 methionine (MET) uptake on positron emission tomography (PET).

Materials and Methods

Eighteen patients with histologically proven primary brain gliomas were included in the study. In addition to conventional MR sequences, dynamic MR images, including a first‐pass gadopentetate dimeglumine T2*‐weighted echo‐planar perfusion sequence and a PET study using MET, were acquired. Eleven patients had low‐grade gliomas, and seven had high‐grade gliomas. rCBV ratios and MET uptake ratios normalized to the contralateral white matter (WM) corresponding values were measured in each tumor. Both maximum rCBV ratios and maximum MET uptake ratios were correlated to histopathology. The maximum rCBV ratios were correlated to the maximum MET uptake ratios.

Results

Both the maximum rCBV ratios and maximum MET uptake ratios of high‐grade gliomas were significantly higher than those of low‐grade gliomas (P < 0.05). There was a significant positive correlation between maximum rCBV ratios and maximum MET uptake ratios (Spearman: r = 0.89, P < 0.00001).

Conclusion

The maximum rCBV ratio and maximum MET uptake ratio are significantly correlated in gliomas, reflecting a close link between amino acid uptake and vascularity in these tumors. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Vibrational spectra of ScAsO4·H2O
Authors: Baran Enrique J. , Schwendtner Karolina , Kolitsch Uwe
Published: October 2006

The powder Fourier‐transform (FT) infrared and Raman spectra of ScAsO4· H2O were recorded and are discussed with a factor‐group analysis based on of its known structural characteristics.

Copyright © 2006 John Wiley & Sons, Ltd.
Striatal dopaminergic neurons are lost with Parkinson's disease progression
Authors: Porritt Michelle J. , Kingsbury Ann E. , Hughes Andrew J. , Howells David W.
Published: October 2006

Increased numbers of dopaminergic neurons are described in the striatum of patients with Parkinson's disease. In postmortem striatal tissue from Parkinson's disease patients with short disease duration (≤8 years), the number of dopaminergic neurons is approximately four times that in patients with long duration (≥16 years). The data suggest the possibility that the presence of large numbers of these striatal dopaminergic neurons may be harmful and may accelerate the disease process. Alternatively, these neurons may be lost to the disease process. © 2006 Movement Disorder Society
Botulinum toxin and neuromotor rehabilitation: An integrated approach to idiopathic cervical dystonia
Authors: Tassorelli Cristina , Mancini Francesca , Balloni Laura , Pacchetti Claudio , Sandrini Giorgio , Nappi Giuseppe , Martignoni Emilia
Published: October 2006

Currently, the best treatment option for idiopathic cervical dystonia (ICD) is injection of botulinum toxin (BTX) into the affected muscles, whereas rehabilitative approaches have given disappointing results. We evaluated whether the association of an ad hoc rehabilitative program may improve the clinical efficacy of BTX treatment in a single‐center, cross‐over, controlled study. Forty patients with ICD were randomly assigned to two different treatment groups: (1) BTX type A (BTX‐A) plus a specific program of physical therapy (BTX‐PT) or (2) BTX‐A alone (BTX‐0). Patients in the BTX‐PT group showed a longer duration of the clinical benefit (118.8 vs. 99.1 days) and needed a lower dose of BTX at reinjection (284.5 vs. 325.5 units). In addition, they showed more marked reductions in their disability in activities of daily living (−9.7 vs. −4.85 points) and subjective pain (−13.35 vs. 6.95 points) scores. Association of BTX‐A therapy with a specific program of physical therapy may improve ICD treatment outcome. © 2006 Movement Disorder Society
Everyday activities and social contacts among older deaf sign language users: Relationships to health and well‐being
Authors: Werngren‐Elgström Monica , Brandt Åse , Iwarsson Susanne
Published: October 2006

The purpose of this study was to describe the everyday activities and social contacts among older deaf sign language users, and to investigate relationships between these phenomena and the health and well‐being within this group. The study population comprised deaf sign language users, 65 years or older, in Sweden. Data collection was based on interviews in sign language, including open‐ended questions covering everyday activities and social contacts as well as self‐rated instruments measuring aspects of health and subjective well‐being. The results demonstrated that the group of participants was homogeneous in their productive and leisure activities, regardless of gender and age. The number of productive activities was related to all aspects of health, while the number of leisure activities was related to perceived health and subjective well‐being. No significant relationship was found between aspects of health and subjective well‐being and the frequency of social contacts with family/relatives or visiting the deaf club and meeting friends. It is concluded that the variety of activities at the deaf clubs are important for the subjective well‐being of older deaf sign language users. Further research should investigate the importance and perceived value of the various activities at the deaf clubs. When evaluating the results of this study, the fact that the total number of participants was small, and the dropout rate was high, has to be borne in mind. Copyright © 2006 John Wiley & Sons, Ltd.
Judge Peter Kooijmans Retires from the International Court of Justice
Authors: BRUS MARCEL
Published: October 2006

In February 2006 Judge P. H. Kooijmans retired from the International Court of Justice after having served a full nine-year term. The article focuses on the manner in which Peter Kooijmans has performed his task as a judge by taking a close look at his most significant individual opinions. It focuses on three aspects of his contribution to the work of the Court: settling disputes, applying legal logic, and the development of international law.
Product Placement, Markengedächtnis, Markenimage (2)
Authors: Bock Michael , Kirchgäßner Bettina , Seeliger Viola
Published: October 2006

Zusammenfassung. Nach einer Untersuchung von Bock und Gómez Izquierdo (2006) ist die Wirksamkeit des Product Placement gering, weil Markenprodukte dabei kaum beachtet werden. In einer Folgeuntersuchung haben wir deshalb die Aufmerksamkeit variiert, indem unsere Teilnehmer/innen bei einem James-Bond-Film zwei unterschiedliche Aufgaben erhielten. Bei der ersten Aufgabe sollten sie auf James Bond achten, bei der zweiten auf Markenplatzierungen. Theoretischer Hintergrund war ein Modell, das zwei mögliche Wirkungswege des Product Placement beschreibt: einen expliziten Weg, der eine Beachtung der Markenplatzierungen erfordert, und einen impliziten Weg, der davon unabhängig ist. Tatsächlich wurden die Markenplatzierungen jedoch nur auf dem expliziten Weg wirksam, sichtbar an den expliziten Markenerinnerungen. Die impliziten Markenerinnerungen und die Markenimages wurden dagegen nicht verbessert. Abschließend wird deshalb diskutiert, wie sich die Wirksamkeit des Product Placement auf dem impliziten Weg verbessern lässt.
Magma‐driven subcritical crack growth and implications for dike initiation from a magma chamber
Authors: Chen Zuan , Jin Z.‐H.
Published: October 2006

The purpose of this paper is to explore a viscoelastic energy dissipation theory for subcritical dike growth from a magma chamber. The theoretical relationship between the dike growth velocity and dike length is established using the viscoelastic subcritical crack growth theory proposed by the first author and the solutions of stress intensity factor at the crack tip derived by a perturbation method. Effects of magma chamber over‐pressure, buoyancy and viscoelastic properties of the host rock on the subcritical growth rate are included in the model. The numerical results indicate that the viscous energy dissipation of the host rock could allow a short dike to slowly grow on the order of 10−7–10−5 m/s under modest over‐pressure and to accelerate when the stress intensity factor increases close to the fracture toughness, followed by the unstable dike propagation. The proposed theory provides a reasonable understanding of dike initiation process from a magma chamber.
Lava channel formation via the viscoplastic indentation of hot substrates
Authors: Gioia Gustavo , Chakraborty Pinaki , Kieffer Susan
Published: October 2006

Lava channels that appear to have been incised into the underlying substrate are commonly ascribed to thermal or thermomechanical erosion. Here we show that where the associated lava flow moves on a hot and soft substrate, the channel may also be ascribed to viscoplastic indentation of the substrate. A simple model of viscoplastic indentation leads to distinct predictions that can be readily tested in the field. For example, two broad, wedge‐shaped, levee‐like features should rise from the substrate during indentation. Such features appear to have risen alongside of a channel that was incised into a hot and soft, recently emplaced basaltic substrate during the 2001 eruption on Mount Etna.
A model study of the Angola Benguela Frontal Zone: Sensitivity to atmospheric forcing
Authors: Colberg F. , Reason C. J. C.
Published: October 2006

A regional ocean model is applied to the tropical South East Atlantic Ocean in order to investigate the sensitivity of the intensity and position of the Angola Benguela Frontal Zone. The results suggest that the position of the Angola Benguela Frontal Zone is mainly determined by opposing northward and southward flow within 2 degrees off the coast. The windstress curl plays a major role in altering the position of the Angola Benguela Frontal Zone, as it controls the southeastward flow of the South Equatorial Counter Current. The opposing northward flow is mainly the result of geostrophic adjustment to coastal upwelling driven by the meridional windstress. The strength of the frontal zone is found to be related to the strength of the southerly windstress that controls the coastal upwelling.
Nonlinear evolution of the electron two‐stream instability: Two‐dimensional particle simulations
Authors: Umeda Takayuki , Omura Yoshiharu , Miyake Taketoshi , Matsumoto Hiroshi , Ashour‐Abdalla Maha
Published: October 2006

We studied nonlinear evolution of the electron two‐stream instability in a two‐dimensional system. Electron two‐stream and bump‐on‐tail instabilities are considered to be the most probable generation mechanisms for electrostatic solitary waves and electron holes observed in various regions of the Earth's magnetosphere. We performed two‐dimensional particle‐in‐cell simulations for various sets of electron cyclotron frequencies and initial electron thermal velocities. We found that the nonlinear evolution falls into four groups. When the electron cyclotron frequency is smaller than the bounce frequency of electrons trapped by electron holes, the electron holes become unstable as reported in previous simulations. When the electron cyclotron frequency is larger than the bounce frequency, the stability of electron holes is controlled by their amplitude. In the case of the cold two‐stream instability where the potential energy of excited electrostatic waves becomes larger than the thermal energy of background electrons, electron holes decay into electrostatic whistler waves. In another case, the two‐stream instability develops to form electron holes in runs with high initial electron thermal velocities. When the electron cyclotron frequency is much larger than the electron bounce frequency, we found the formation of stable one‐dimensional electron holes through coalescence. When the electron cyclotron frequency is smaller than twice the bounce frequency, we found formation of two‐dimensional electron holes isolated in both directions parallel and perpendicular to the ambient magnetic field.
Iron is not involved in oxidative stress‐mediated cytotoxicity of doxorubicin and bleomycin
Authors: Kaiserová H , den Hartog G J M , Šimůnek T , Schröterová L , Kvasničková E , Bast A
Published: October 2006

Background and purpose:

The anticancer drugs doxorubicin and bleomycin are well‐known for their oxidative stress‐mediated side effects in heart and lung, respectively. It is frequently suggested that iron is involved in doxorubicin and bleomycin toxicity. We set out to elucidate whether iron chelation prevents the oxidative stress‐mediated toxicity of doxorubicin and bleomycin and whether it affects their antiproliferative/proapoptotic effects.

Experimental approach:

Cell culture experiments were performed in A549 cells. Formation of hydroxyl radicals was measured in vitro by electron paramagnetic resonance (EPR). We investigated interactions between five iron chelators and the oxidative stress‐inducing agents (doxorubicin, bleomycin and H2O2) by quantifying oxidative stress and cellular damage as TBARS formation, glutathione (GSH) consumption and lactic dehydrogenase (LDH) leakage. The antitumour/proapoptotic effects of doxorubicin and bleomycin were assessed by cell proliferation and caspase‐3 activity assay.

Key results:

All the tested chelators, except for monohydroxyethylrutoside (monoHER), prevented hydroxyl radical formation induced by H2O2/Fe2+ in EPR studies. However, only salicylaldehyde isonicotinoyl hydrazone and deferoxamine protected intact A549 cells against H2O2/Fe2+. Conversely, the chelators that decreased doxorubicin and bleomycin‐induced oxidative stress and cellular damage (dexrazoxane, monoHER) were not able to protect against H2O2/Fe2+.

Conclusions and implications:

We have shown that the ability to chelate iron as such is not the sole determinant of a compound protecting against doxorubicin or bleomycin‐induced cytotoxicity. Our data challenge the putative role of iron and hydroxyl radicals in the oxidative stress‐mediated cytotoxicity of doxorubicin and bleomycin and have implications for the development of new compounds to protects against this toxicity.

British Journal of Pharmacology (2006) 149, 920–930. doi:10.1038/sj.bjp.0706930
Correlated-intensity velocimeter for arbitrary reflector for laser-produced plasma experiments
Authors: Wang Zhehui , Luo Sheng-Nian , Barnes Cris W. , Briggs Matthew E. , Paisley Dennis L. , Paul Stephen F.
Published: October 2006

A laser-based technique, called correlated-intensity velocimeter for arbitrary reflector (CIVAR), is described for velocity measurement of reflecting surfaces in real time. Velocity versus time is an important measurement in laser-produced high-energy density plasma experiments because the motion of the surface depends on both the equation of the state of the surface material and laser-produced plasma. The physics and working principle of CIVAR are the same as those of a previous concept that resolves Doppler shift of plasma light emission using a pair of narrow passband interference filters. One unique feature of CIVAR is that a reflected laser beam is used instead of plasma emission. Therefore, CIVAR is applicable to both emitting and nonemitting reflecting surfaces. Other advantages of CIVAR include its simplicity, lower cost, and unambiguous data analysis that can be fully automated. The design of a single-point CIVAR is described in detail with emphasis on laser wavelength selection and signal-to-noise ratio. The single-point CIVAR system can be expanded into a multiple-point system straightforwardly. It is possible to use CIVAR concept to construct a two-dimensional imaging system for a nonuniform velocity field of a large reflecting surface; such a velocity imaging system may have applications beyond laser-produced plasma experiments, for example, in shock compression of condensed matter.
Subgrid-scale modeling of compressible magnetohydrodynamic turbulence in heat-conducting plasma
Authors: Chernyshov A. A. , Karelsky K. V. , Petrosyan A. S.
Published: October 2006

A large-eddy simulation (LES) approach for compressible magnetohydrodynamic (MHD) turbulence in heat-conducting plasma is developed for the first time. Subgrid-scale models for new terms appearing due to the presence of magnetic field are suggested. Results of modeling for decaying compressible MHD turbulence are presented. Comparison and testing with results obtained by direct numerical simulation are made. The efficiency of the developed LES technique for compressible MHD turbulence in heat-conducting plasma is shown.
Visualization of mRNA translation in living cells
Authors: Rodriguez Alexis J. , Shenoy Shailesh M. , Singer Robert H. , Condeelis John
Published: October 2006

The role of mRNA localization is presumably to effect cell asymmetry by synthesizing proteins in specific cellular compartments. However, protein synthesis has never been directly demonstrated at the sites of mRNA localization. To address this, we developed a live cell method for imaging translation of β-actin mRNA. Constructs coding for β-actin, containing tetracysteine motifs, were transfected into C2C12 cells, and sites of nascent polypeptide chains were detected using the biarsenial dyes FlAsH and ReAsH, a technique we call translation site imaging. These sites colocalized with β-actin mRNA at the leading edge of motile myoblasts, confirming that they were translating. β-Actin mRNA lacking the sequence (zipcode) that localizes the mRNA to the cell periphery, eliminated the translation there. A pulse-chase experiment on living cells showed that the recently synthesized protein correlated spatially with the sites of its translation. Additionally, localization of β-actin mRNA and translation activity was enhanced at cell contacts and facilitated the formation of intercellular junctions.