bluuebunny/crossref_metadata_2025 huggingface dataset:
Seats That May Not Matter: Testing for Racial Polarization in U.S. City Councils
Authors: AUSTIN RORY ALLAN
Published: February 2008

Abstract: Critics of the Voting Rights Act claim that electoral structures used by city councils lead to racially polarized legislatures in which African American members are consistently outvoted by white majorities. Using council votes from six cities, this study shows that the critics' claim is exaggerated. In only one city were African American council members generally less likely to be on the winning side of votes because of their race. Polarization is more of a concern for particular issues: members with large black constituencies were less likely to be on the winning side of votes on housing or police affairs in four cities.
Tangent circles
Authors: Stanley P.
Published: February 2008

The work presented here was prompted by curiosity concerning a structural detail of the ironwork supporting the overhead cover of the railway platform at Stockport, Cheshire. The detail – see the front cover which shows the roof support – comprises an elliptical ‘quadrant’ joined to vertical and horizontal members of the supporting structure, with a circular ring fitted interstitially so as to touch the elliptical arc and the two straight members. The question arises: what is the radius of the circular ring in terms of the parameters of the ellipse?
Partitioning a set
Authors: Lewis Barry
Published: February 2008

This article grew out of a problem that I saw in an old textbook on sale in a second hand bookshop. It inspired a generalisation that leads to two sets of well known numbers (Bell and Stirling numbers), and then to a new result for one of them.
The Aesthetics of Ascension in Norman Bel Geddes's Futurama
Authors: Morshed Adnan
Published: February 2008

The present article concerns the early-twentieth-century avant-garde's aestheticizing of a new vision occasioned by the advent of human flight. It focuses on the project that best reflects this vision: the Futurama, an exhibit created by the American industrial designer Norman Bel Geddes for the 1939 New York World's Fair. The Futurama's status as the "number one hit show" of the fair derived largely from its theatrical technique of seeing: spectators literally gazed down on an American utopia as if they were aviators in a low-flying airplane. Conceived during the golden age of American aviation, in the 1920s and 1930s, the Futurama exemplified the common utopian belief that the perspective from an airplane would usher in new spatial dynamics that would introduce the city of the future. The enthusiasm for aerial vision evinced a remarkable affiliation between aviation and a modernist logic of looking at the world. The fact that the Futurama spectator's aerial viewing became enmeshed in broader conceptualizations of twentieth-century visuality reveals the crucial presence of what could be called an "aesthetics of ascension" in the avantgarde imagination of the future city.
The Bat Creek Stone Revisited: A Fraud Exposed
Authors: Mainfort Robert C. , Kwas Mary L.
Published: February 2008

An inscribed stone reportedly excavated by an employee of the Smithsonian Institution from a burial mound in eastern Tennessee, and published by Cyrus Thomas in his 1894 landmark report, has been promoted by transatlantic contact enthusiasts as incontrovertible proof of Precolumbian Old World contacts. The inscription is fraudulent, having been copied from a Masonic treatise. We present the source of the inscription and discuss other circumstances concerning the stone and its purported discovery.
Coscinocladium, an overlooked endemic and monotypic Mediterranean lichen genus of Physciaceae, reinstated by molecular phylogenetic analysis
Authors: Crespo Ana , Blanco Oscar , Llimona Xavier , Ferencová Zuzana L. , Hawksworth David L.
Published: February 2008

The position of the sterile western Mediterranean crustose–placodioid lichen generally known as Lecanora lisbonenesis has been investigated using mitochondrial SSU rDNA sequence data. It proves to belong to an independent genus of Physciaceae, for which the generic name Coscinocladium is available, and the earliest species name is Variolaria gaditana. Previous reports of apothecia in the species prove to be a result of mixtures with other lichen species. A lectotype is selected for L. lisbonensis, a neotype designated for V. gaditana, and the new combination Coscinocladium gaditanum made. The species is described, illustrated, its ecology discussed, and a distribution map provided.
Preclassic Obsidian Procurement and Utilization at the Maya Site of Colha, Belize
Authors: Brown David O. , Dreiss Meredith L. , Hughes Richard E.
Published: February 2008

This study explores the early use of obsidian at the Maya site of Colha in northern Belize and the implications that variations in source distribution have for the site and its regional connections. Energy dispersive x-ray fluorescence (EDXRF) analysis of 104 specimens of obsidian from Preclassic contexts at the site identified El Chayal obsidian as the most common overall followed closely by that from San Martin Jilotepeque. Ixtepeque obsidian, not common in many Preclassic assemblages, was also strongly represented. The results revealed a Middle Preclassic dependence on San Martin obsidian gradually diminishing through the Preclassic to the Classic period, when San Martin all but disappears from the site. A corresponding increase in El Chayal obsidian use through time at Colha coincides with the rise of Kaminaljuyu in the Guatemalan highlands. Analysis of the obsidian by context indicated that El Chayal obsidian dominated in architectural and ritual deposits while Ixtepeque obsidian was the most common in workshops. San Martin accounted for a slightly greater percentage than El Chayal obsidian in middens, with Ixtepeque materials notably less common. The data indicate that Colha was connected to a broad distribution network from the Middle Preclassic onward, and that obsidian source variability was greater during the Preclassic than the subsequent Classic period.
Jews, Ukrainians, and Russians in Kiev: Intergroup Relations in Late Imperial Associational Life
Authors: Meir Natan M.
Published: February 2008

This article explores the associational life of late imperial Kiev to gauge the extent of Jewish participation in the city's civil society and the nature of interethnic relations in the voluntary sphere. Natan Meir demonstrates that, despite political and societal circumstances that often discouraged positive interactions between Jews and their Russian and Ukrainian neighbors, the voluntary association made possible opportunities for constructive interethnic encounters. These opportunities included a range of experiences from full Jewish integration to a segregation of Jewish interests within the sphere of activity of a particular association. While taking into account the central role of intergroup tensions and hostility in Kiev, Meir notes that the frequency of contacts between Jews and non-Jews was higher than most scholars have assumed. By placing the case of Kiev against the larger framework of the Russian empire as well as other European states, Meir contributes to our understanding of the development of late imperial civil society and of the modern Jewish experience in the late Russian empire and across urban Europe.
Eugenics, Rejuvenation, and Bulgakov's Journey into the Heart of Dogness
Authors: Howell Yvonne
Published: February 2008

This new reading of Mikhail Bulgakov's Heart of a Dog challenges the two lines of thought that dominate existing interpretations. Cold Warinspired critics saw in the banned novella an anti-Soviet political allegory and ignored its astute treatment of Soviet debates on biosocial issues. Most other critics have cast Preobrazhenskii as a mad scientist in the Frankenstein tradition, unleashing forces he himself cannot control. Putting aside false antitheses, Bulgakov's novella emerges as a fictional exploration of ideas in eugenics, hormone replacement therapy, and the nature-nurture debate that had real urgency for early Soviet geneticists struggling for ideological support, and for Bolshevik policymakers trying to create a “New Soviet Man.” In this article, Yvonne Howell describes the competing scientific paradigms that provide a backdrop to Bulgakov's work and shows how attitudes from across the “nature-nurture” spectrum appear and interact in Heart of a Dog through the voices of its principal characters.
Kernel‐based learning for biomedical relation extraction
Authors: Li Jiexun , Zhang Zhu , Li Xin , Chen Hsinchun
Published: February 2008

Relation extraction is the process of scanning text for relationships between named entities. Recently, significant studies have focused on automatically extracting relations from biomedical corpora. Most existing biomedical relation extractors require manual creation of biomedi‐cal lexicons or parsing templates based on domain knowledge. In this study, we propose to use kernel‐based learning methods to automatically extract biomedical relations from literature text. We develop a framework of kernel‐based learning for biomedical relation extraction. In particular, we modified the standard tree kernel function by incorporating a trace kernel to capture richer contextual information. In our experiments on a biomedi‐cal corpus, we compare different kernel functions for biomedical relation detection and classification. Theexperimental results show that a tree kernel outperforms word and sequence kernels for relation detection, our trace‐tree kernel outperforms the standard tree kernel, and a composite kernel outperforms individual kernels for relation extraction.
A stochastic model for predicting dextrose equivalent and saccharide composition during hydrolysis of starch by α‐amylase
Authors: Besselink Tamara , Baks Tim , Janssen Anja E.M. , Boom Remko M.
Published: February 2008

A stochastic model was developed that was used to describe the formation and breakdown of all saccharides involved during α‐amylolytic starch hydrolysis in time. This model is based on the subsite maps found in literature for Bacillus amyloliquefaciens α‐amylase (BAA) and Bacillus licheniformis α‐amylase (BLA). Carbohydrate substrates were modeled in a relatively simple two‐dimensional matrix. The predicted weight fractions of carbohydrates ranging from glucose to heptasaccharides and the predicted dextrose equivalent showed the same trend and order of magnitude as the corresponding experimental values. However, the absolute values were not the same. In case a well‐defined substrate such as maltohexaose was used, comparable differences between the experimental and simulated data were observed indicating that the substrate model for starch does not cause these deviations. After changing the subsite map of BLA and the ratio between the time required for a productive and a non‐productive attack for BAA, a better agreement between the model data and the experimental data was observed. Although the model input should be improved for more accurate predictions, the model can already be used to gain knowledge about the concentrations of all carbohydrates during hydrolysis with an α‐amylase. In addition, this model also seems to be applicable to other depolymerase‐based systems. Biotechnol. Bioeng. 2008;100: 684–697. © 2008 Wiley Periodicals, Inc.
High‐throughput microplate technique for enzymatic hydrolysis of lignocellulosic biomass
Authors: Chundawat Shishir P.S. , Balan Venkatesh , Dale Bruce E.
Published: February 2008

Several factors will influence the viability of a biochemical platform for manufacturing lignocellulosic based fuels and chemicals, for example, genetically engineering energy crops, reducing pre‐treatment severity, and minimizing enzyme loading. Past research on biomass conversion has focused largely on acid based pre‐treatment technologies that fractionate lignin and hemicellulose from cellulose. However, for alkaline based (e.g., AFEX) and other lower severity pre‐treatments it becomes critical to co‐hydrolyze cellulose and hemicellulose using an optimized enzyme cocktail. Lignocellulosics are appropriate substrates to assess hydrolytic activity of enzyme mixtures compared to conventional unrealistic substrates (e.g., filter paper, chromogenic, and fluorigenic compounds) for studying synergistic hydrolysis. However, there are few, if any, high‐throughput lignocellulosic digestibility analytical platforms for optimizing biomass conversion. The 96‐well Biomass Conversion Research Lab (BCRL) microplate method is a high‐throughput assay to study digestibility of lignocellulosic biomass as a function of biomass composition, pre‐treatment severity, and enzyme composition. The most suitable method for delivering milled biomass to the microplate was through multi‐pipetting slurry suspensions. A rapid bio‐enzymatic, spectrophotometric assay was used to determine fermentable sugars. The entire procedure was automated using a robotic pipetting workstation. Several parameters that affect hydrolysis in the microplate were studied and optimized (i.e., particle size reduction, slurry solids concentration, glucan loading, mass transfer issues, and time period for hydrolysis). The microplate method was optimized for crystalline cellulose (Avicel) and ammonia fiber expansion (AFEX) pre‐treated corn stover. Biotechnol. Bioeng. 2008;99: 1281–1294. © 2008 Wiley Periodicals, Inc.
Co‐immobilization of dextransucrase and dextranase for the facilitated synthesis of isomalto‐oligosaccharides: Preparation, characterization and modeling
Authors: Erhardt Frank A. , Kügler Jonas , Chakravarthula Raghavender R. , Jördening Hans‐Joachim
Published: February 2008

Co‐Immobilization of dextransucrase (DS) and dextranase (DN) into calcium alginate includes the co‐entrapment of soluble DS and adsorbed DN. DS converts sucrose into dextran, which is the substrate for DN, so that isomalto‐oligosaccharides (IMOs) are follow‐up products of dextran hydrolysis. The boundary conditions for the successful preparation are investigated with respect to choice of DN adsorbate, surface modifications using blotting agents and optimal enzyme activity ratios. Further, repetitive batch experiments suggest the selection of medium activity ratios for continuous use (0.3 UDNU−1DS, e.g.). Product formation at various cosubstrate:substrate concentrations as well as at different DN:DS ratios are discussed. Moreover, the complexity of the bi‐enzymatic system can be reduced considering the molar ratios of cosubstrate:substrate (glucose:sucrose). Based on these factors, a mechanistic kinetic model is developed, which distinguishes the corresponding contributions of the two enzymes upon overall product formation. In general, at low glucose:sucrose ratios isomaltose synthesis is featured primarily by DN action. Yet with increasing amounts of glucose both the quantity and quality of DN substrate changes, so that its contribution to product formation decreases in an exponential manner; still the overall product yield continuously increases due to enhanced DS contribution. Biotechnol. Bioeng. 2008;100: 673–683. © 2008 Wiley Periodicals, Inc.
Bacterial chemotaxis transverse to axial flow in a microfluidic channel
Authors: Lanning Larry M. , Ford Roseanne M. , Long Tao
Published: February 2008

Swimming bacteria sense and respond to chemical signals in their environment. Chemotaxis is the directed migration of a bacterial population toward increasing concentrations of a chemical that they perceive to be beneficial to their survival. Bacteria that are indigenous to groundwater environments exhibit chemotaxis toward chemical contaminants such as hydrocarbons, which they are also able to degrade. This phenomenon may facilitate bioremediation processes by bringing bacteria into closer proximity to these contaminants. A microfluidic device was assembled to study chemotaxis transverse to advective flow. Using a T‐shaped channel design (T‐sensor), two fluid streams were brought into contact by impinging flow. They then flowed adjacent to each other along a transparent channel. An advantage to this design is that it allows real‐time visualization of bacterial distributions within the channel. Under laminar flow conditions a chemotactic driving force was created perpendicular to the direction of flow by diffusion of the chemical attractant from one input stream to the other. A comparison of the chemotactic band behavior in the absence and presence of flow showed that fluid velocity did not significantly impede chemotactic migration in the transverse direction. Biotechnol. Bioeng. 2008;100: 653–663. © 2008 Wiley Periodicals, Inc.
Design of Hydrophobic Polyoxometalate Hybrid Assemblies Beyond Surfactant Encapsulation
Authors: Song Yu‐Fei , McMillan Nicola , Long De‐Liang , Thiel Johannes , Ding Yulong , Chen Haisheng , Gadegaard Nikolaj , Cronin Leroy
Published: February 2008

Grafting of C‐6, C‐16 and C‐18 alkyl chains onto the hydrophilic Mn‐Anderson clusters (compounds 2–4) has been achieved. Exchange of the tetrabutyl ammonium (TBA) with dimethyldioctadecyl ammonium (DMDOA) results in the formation of new polyoxometalate (POM) assemblies (compounds 5–6), in which the POM cores are covalently functionalized by hydrophilic alkyl‐chains and enclosed by surfactant of DMDOABr. As a result, we have been able to design and synthesize POM‐containing hydrophobic materials beyond surfactant encapsulation. In solid state, scanning electron and transmission electron microscopy (SEM and TEM) studies of the TBA salts of compounds 3 and 4 show highly ordered, uniform, reproducible assemblies with unique segmented rodlike morphology. SEM and TEM studies of the DMDOA salts of compounds 5 and 6 show that they form spherical and sea urchin 3D objects in different solvent systems. In solution, the physical properties of compound 5 and 6 (combination of surfactant‐encapsulated cluster (SEC) and surface‐grafted cluster (SGC)) show a liquid‐to‐gel phase transition in pure chloroform below 0 °C, which are much lower than other reported SECs. By utilizing light scattering measurements, the nanoparticle size for compounds 5 and 6 were measured at 5 °C and 30 °C, respectively. Other physical properties including differential scanning calorimetry have been reported.
Design and construction of a microcoil NMR probe for the routine analysis of 20‐μL samples
Authors: Henry Ian D. , Park Gregory H.J. , Kc Ravi , Tobias Brian , Raftery Daniel
Published: February 2008

Recent advances in microcoil NMR have provided commercially available, robust methodologies for analyzing mass and volume limited samples in the low microliter regime, and the technology has been applied in a number of areas. Unfortunately, due to constraints on sample size and the limited solubility of some compounds of interest, the application of this approach to certain areas of development, such as the structural analysis of chromatography eluates, is restricted. A current challenge is to provide an option within a previously unexplored sample size regime (tens of microliters) while still taking advantage of the increase in mass sensitivity afforded by solenoidal microcoil NMR. In this article, we present the design and construction of a microcoil NMR probe with a custom detection cell for the routine analysis of 20‐μL samples. The detection cell is comprised of a CO2‐laser‐heated HF‐etched borosilicate active volume with fused silica transfer lines added to provide sample input and output. This setup produces an enlarged sample bubble within the detection coil and provides easy connection with 1/16 in. standard LC connections, lending itself to applications with HPLC‐NMR, online SPE and similar separation techniques, as well as higher‐throughput robotic automation. NMR performance characteristics determined using standard compounds showed the probe exhibited reasonable resolution (<0.01 ppm), although sensitivity was less than optimal due to tuning constraints. Future improvements and opportunities are also discussed. © 2008 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 33B: 1–8, 2008
Minimizing the induced fields in MRI occupational workers by lowering the imager
Authors: Trakic A. , Wang H. , Liu F. , Lopez H.S. , Weber E. , Crozier S.
Published: February 2008

In magnetic resonance imaging (MRI), healthcare workers can be exposed to strong static and time‐varying magnetic fields outside the imager. Body motion through the large, spatially nonuniform static magnetic field generated by the main magnet and exposure to low‐frequency magnetic fields from pulsed gradient coils can lead to the stimulation of electric fields in the body. Tissue of the central and peripheral nervous system (CPNS) in the head and torso is particularly susceptible. To protect occupational workers, the member states of the European Union are required to incorporate the physical agents directive (PAD) 2004/40/EC into their legislation, which could restrict the use of MRI in some cases. This article reports a rather simple and general method/solution that can notably reduce the head/trunk exposure of MRI operators to both static and (low‐frequency) time‐dependant magnetic fields in MRI. It is numerically shown that the upper body CPNS exposure can be reduced by factors of up to 50 or more, when the MRI machine is simply lowered by 1 m in height relative to the ground floor. The proposed approach can lead to significantly reduced in situ electric fields/current in the upper body and thus allow faster worker motions around the lowered imager. © 2008 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 33B: 39–54, 2008
Wilms tumor gene protein 1 is associated with ovarian cancer metastasis and modulates cell invasion
Authors: Barbolina Maria V. , Adley Brian P. , Shea Lonnie D. , Stack M. Sharon
Published: February 2008

BACKGROUND

Although metastatic disease is the primary cause of death from epithelial ovarian carcinoma, to the authors' knowledge the cellular mechanisms that regulate intraperitoneal metastasis are largely unknown. Metastasizing ovarian carcinoma cells encounter a collagen‐rich microenvironment because the submesothelial matrix is comprised mainly of interstitial collagens Types I and III.

METHODS

Immunohistochemistry using primary and metastatic ovarian carcinoma samples was employed to detect expression of Wilms tumor gene protein 1 (WT1). Three‐dimensional (3D) collagen culture, real‐time reverse transcriptase‐polymerase chain reaction, and immunofluorescent staining were used to evaluate changes in WT1 RNA and protein expression in response to 3D collagen culture. Boyden chamber invasion assay, scratch‐wound motility assay, and Western blot analysis were used to establish the function of WT1 in ovarian carcinoma cells.

RESULTS

To model intraperitoneal invasion in vitro, ovarian cancer cells were cultured in a 3D collagen microenvironment. 3D collagen culture resulted in robust induction of WT1 at the mRNA and protein levels. WT1 expression was prevalent in primary ovarian tumors and was retained in paired peritoneal metastases. Functional studies supported a role for WT1 in intraperitoneal invasion, because siRNA knockdown of WT1 expression reduced the ability of ovarian cancer cells to invade 3D collagen gels.

CONCLUSIONS

The data from the current study identify a novel regulatory mechanism for the control of WT1 expression and provide evidence for a functional role of WT1 protein in the control of cellular invasive activity. Cancer 2008. ©2008 American Cancer Society.
Tuning of cell proliferation on tough gels by critical charge effect
Authors: Chen Yong Mei , Gong Jian Ping , Tanaka Masaru , Yasuda Kazunori , Yamamoto Sadaaki , Shimomura Masatsugu , Osada Yoshihito
Published: February 2008

Tough triple network (TN) hydrogels that facilitate cell spreading and proliferation and, at the same time, preserve high mechanical strength are synthesized by the introduction of a proper component of negatively charged moiety, poly(2‐acrylamido‐2‐methyl‐propane sulfonic acid sodium salt) (PNaAMPS), on which cells proliferate, with neutral moiety, poly(N,N‐dimethylacrylamide) (DMAAm), on which cells do not proliferate, as the third network component, to PNaAMPS/PDMAAm double network (DN) gels. For synthesizing the tough TN gels to support cell viability, the effect of charge density on the behaviors of three kinds of cells, bovine fetal aorta endothelial cells (BFAECs), human umbilical endothelial cells (HUVECs), and rabbit synovial tissue‐derived fibroblast cells (RSTFCs) were systematically investigated on poly(NaAMPS‐co‐DMAAm) gels with different charge density. The charge density of the gels was tuned by changing the molar fraction (F) of negatively charged monomer in the copolymer hydrogels. Critical F, which corresponds to a critical value of the zeta potential (ζ), is observed for cell spreading and proliferation. The critical F for BFAECs and HUVECs proliferate to confluent is F = 0.4 (ζ = −20 mV), whereas the critical F for RSTFCs shifts to F = 0.7 (ζ = −28.5 mV). The effect of gel charge density on cell behavior is correlated well with the total adsorbed proteins and fibronectin. By applying these results, cell proliferation is successfully realized on the tough TN hydrogels without surface modification with any cell adhesive proteins or peptides. The results will substantially promote the application of tough hydrogels as soft and wet tissues. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Protective effects of R‐alpha‐lipoic acid and acetyl‐L‐carnitine in MIN6 and isolated rat islet cells chronically exposed to oleic acid
Authors: Shen Weili , Liu Kai , Tian Chuan , Yang Lu , Li Xuesen , Ren Jinmin , Packer Lester , Head Elizabeth , Sharman Edward , Liu Jiankang
Published: February 2008

Mitochondrial dysfunction due to oxidative stress and concomitant impaired β‐cell function may play a key role in type 2 diabetes. Preventing and/or ameliorating oxidative mitochondrial dysfunction with mitochondria‐specific nutrients may have preventive or therapeutic potential. In the present study, the oxidative mechanism of mitochondrial dysfunction in pancreatic β‐cells exposed to sublethal levels of oleic acid (OA) and the protective effects of mitochondrial nutrients [R‐alpha‐lipoic acid (LA) and acetyl‐L‐carnitine (ALC)] were investigated. Chronic exposure (72 h) of insulinoma MIN6 cells to OA (0.2–0.8 mM) increased intracellular oxidant formation, decreased mitochondrial membrane potential (MMP), enhanced uncoupling protein‐2 (UCP‐2) mRNA and protein expression, and consequently, decreased glucose‐induced ATP production and suppressed glucose‐stimulated insulin secretion. Pretreatment with LA and/or ALC reduced oxidant formation, increased MMP, regulated UCP‐2 mRNA and protein expression, increased glucose‐induced ATP production, and restored glucose‐stimulated insulin secretion. The key findings on ATP production and insulin secretion were verified with isolated rat islets. These results suggest that mitochondrial dysfunction is involved in OA‐induced pancreatic β‐cell dysfunction and that pretreatment with mitochondrial protective nutrients could be an effective strategy to prevent β‐cell dysfunction. J. Cell. Biochem. 104: 1232–1243, 2008. © 2008 Wiley‐Liss, Inc.
Attention mediates radiation's impact on daily living skills in children treated for brain tumors
Authors: Papazoglou Aimilia , King Tricia Z. , Morris Robin D. , Morris Mary K. , Krawiecki Nicolas S.
Published: February 2008

Background

Radiotherapy is associated with an increased survival rate in children with brain tumors, but also with cognitive decline. This study examined the time‐dependent effects of radiation treatment on adaptive functioning in children with brain tumors. The potentially mediating effects of attention span (Trial 1 of the Rey Auditory Verbal Learning Test [RAVLT]) assessed within 7 years of diagnosis were explored.

Procedure

Twenty‐two children treated with cranial radiation for third ventricle or cerebellar tumors were included in this archival study. The mean age at diagnosis was 7.62 years (SD = 4.78) and 10.16 years (SD = 3.83) at evaluation. We examined the extent to which auditory attention span was able to mediate the relationship between time elapsed since the initiation of radiation treatment (M = 2.43 years; SD = 2.37) and adaptive functioning (Vineland Adaptive Behavior Scales [VABS]).

Results

Attention span was found to mediate the relationship between time since the initiation of radiation and daily living skills. These findings were shown to be specific to attention and not a reflection of generalized neuropsychological decline, nor were they a result of increasing time since diagnosis in and of itself.

Conclusions

The results of this study suggest that time since radiation may directly decrease attention and poor attention in turn may be associated with lower adaptive functioning on tasks of daily living. Pediatr Blood Cancer 2008;50:1253–1257. © 2008 Wiley‐Liss, Inc.
Unfolding energetics and stability of banana lectin
Authors: Gupta Garima , Sinha Sharmistha , Surolia Avadhesha
Published: February 2008

The unfolding pathway of banana lectin from Musa paradisiaca was determined by isothermal denaturation induced by the chaotrope GdnCl. The unfolding was found to be a reversible process. The data obtained by isothermal denaturation provided information on conformational stability of banana lectin. The high values of ΔG of unfolding at various temperatures indicated the strength of intersubunit interactions. It was found that banana lectin is a very stable and denatures at high chaotrope concentrations only. The basis of the stability may be attributed to strong hydrogen bonds of the order 2.5–3.1 Å at the dimeric interface along with the presence of water bridges. This is perhaps very unique example in proteins where subunit association is not a consequence of the predominance of hydrophobic interactions. Proteins 2008. © 2008 Wiley‐Liss, Inc.
New crystal structures of ColE1 Rom and variants resulting from mutation of a surface exposed residue: Implications for RNA‐recognition
Authors: Struble E. B. , Ladner J. E. , Brabazon D. M. , Marino J. P.
Published: February 2008

In ColE1, the plasmid encoded RNA one modulator (Rom) protein, which is also referred to as Rop, specifically binds and stabilizes an intermediate RNA loop–loop kissing structure formed between the plasmid encoded transcripts RNA I and RNA II and thereby acts as an auxiliary repressor of replication. Rom folds into a homodimeric, cylindrically packed four helix bundle with an exact twofold symmetry axis (Banner et al., J Mol Biol 1987;196:657–675; Eberle et al., J Biomol 1991;1:71–83). Previous studies (Castagnoli et al., EMBO J 1989;8:621–629; Predki et al., Cell 1995;80:41–50) have localized the RNA binding surface to the H1/H1′ face of the helical bundle and found Phe14 to be a key determinant of the binding affinity and specificity for RNA kissing complexes. To investigate the role of Phe14 in RNA recognition, we have determined high‐resolution crystal structures of two point mutants of Rom (F14Y and F14W), as well as a high‐resolution structure of a crystal form of Rom in which the dimer comprises the asymmetric unit. Although the structures of F14Y and F14W share a very high degree of structural identity with that of the wild‐type protein and each other, differences are observed between the three polypeptide chains found in the asymmetric unit of each crystal in the packing of the tryptophan and tyrosine side chains at position 14, as well as some of the other surface exposed side chains of key amino acids involved in RNA binding. In both the wild‐type Rom and mutant structures, crystal packing forces can break the exact twofold symmetry of the dimer and influence the conformation of the side chains presented on the H1/H1′ face of Rom. Since the new structures show such a high degree of structural identity, the disruption in RNA binding observed for the mutant proteins can be attributed specifically to the chemical nature of the side chain at position 14. Moreover, the fact that even subtle changes in the side chain at position 14 cannot be compensated for by the apparent flexibility of this side chain suggests a highly constrained packing of this residue in the RNA–protein complex. Proteins 2008. Published 2008 Wiley‐Liss, Inc.
Genome wide analysis of pathogenic SH2 domain mutations
Authors: Lappalainen Ilkka , Thusberg Janita , Shen Bairong , Vihinen Mauno
Published: February 2008

The authors have made a genome‐wide analysis of mutations in Src homology 2 (SH2) domains associated with human disease. Disease‐causing mutations have been detected in the SH2 domains of cytoplasmic signaling proteins Bruton tyrosine kinase (BTK), SH2D1A, Ras GTPase activating protein (RasGAP), ZAP‐70, SHP‐2, STAT1, STAT5B, and the p85α subunit of the PIP3. Mutations in the BTK, SH2D1A, ZAP70, STAT1, and STAT5B genes have been shown to cause diverse immunodeficiencies, whereas the mutations in RASA1 and PIK3R1 genes lead to basal carcinoma and diabetes, respectively. PTPN11 mutations cause Noonan sydrome and different types of cancer, depending mainly on whether the mutation is inherited or sporadic. We collected and analyzed all known pathogenic mutations affecting human SH2 domains by bioinformatics methods. Among the investigated protein properties are sequence conservation and covariance, structural stability, side chain rotamers, packing effects, surface electrostatics, hydrogen bond formation, accessible surface area, salt bridges, and residue contacts. The majority of the mutations affect positions essential for phosphotyrosine ligand binding and specificity. The structural basis of the SH2 domain diseases was elucidated based on the bioinformatic analysis. Proteins 2008. © 2008 Wiley‐Liss, Inc.
Peptide and protein loading into porous silicon wafers
Authors: Prestidge C. A. , Barnes T. J. , Mierczynska‐Vasilev A. , Kempson I. , Peddie F. , Barnett C.
Published: February 2008

The influence of peptide/protein size and hydrophobicity on the physical and chemical aspects of loading within porous silicon (pSi) wafer samples has been determined using Atomic Force Microscopy (AFM) and Time‐of‐Flight Secondary Ion Mass Spectroscopy (ToF‐SIMS). Both Gramicidin A (a small hydrophobic peptide) and Papain (a larger hydrophilic protein) were observed (ToF‐SIMS) to penetrate across the entire pSi layer, even at low loading levels. AFM surface imaging of pSi wafers during peptide/protein loading showed that surface roughness increased with Papain loading, but decreased with Gramicidin A loading. For Papain, the loading methodology was also found to influence loading efficiency. These differences indicate more pronounced surface adsorption of Papain. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Can silicon change photonics?
Authors: Jalali Bahram
Published: February 2008

The electronic chip industry embodies the height of technological sophistication and economics of scale. The industry mass produces complex circuitry, boasting over one billion components at such low cost that they appear in consumer products. Fabricating inexpensive photonic components by leveraging this mighty manufacturing infrastructure has been the impetus behind the development of silicon photonics. If it can be done economically and in an energy‐efficient manner, empowering silicon with optical functionality will bring optical communications to the realm of computers where limitations of metallic interconnects are threatening the industry's future. Guided by such visions and propelled by pioneering research conducted in the 1980s and 1990s, silicon photonics has enjoyed spectacular progress in the last six years. The critical size of photonic devices has been scaled to the 300 nm regime making more efficient use of wafer real estate. Optical amplification and lasing, once considered forbidden in silicon, have recently been demonstrated. High‐speed and efficient electrical‐optical conversion is being performed by production‐worthy devices. Silicon's nonlinear optical properties, enhanced by tight optical confinement in Si/SiO2structures, are producing wavelength switching and generation, which are central functions in multiwavelength communications and signal processing. This article reviews these and other exciting progress being made in silicon photonics and identifies the challenges that remain on the path to commercialization. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Indium oxide thin film transistors via reactive sputtering using metal targets
Authors: Qijun Yao , Dejie Li
Published: February 2008

Thin film transistors with In2O3 channel were fabricated. The channel layer of In2O3 and gate dielectric of Ta2O5 in the device was deposited by reactive sputtering using metal targets. A thin layer of Bi was deposited on the channel and then an‐ nealed to help stabilize the device performance. The device with optimal dose of Bi exhibited a channel mobility of 12 cm2/V s. Effects of Bi layer and influence of gate dielectric to the device performance are investigated. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A mass filter based on an accelerating traveling wave
Authors: Wiedenbeck Michael , Kasemset Bodin , Kasper Manfred
Published: February 2008

We describe a novel mass filtering concept based on the acceleration of a pulsed ion beam through a stack of electrostatic plates. A precisely controlled traveling wave generated within such an ion guide will induce a mass‐selective ion acceleration, with mass separation ultimately accomplished via a simple energy‐filtering system. Crucial for successful filtering is that the velocity with which the traveling wave passes through the ion guide must be dynamically controlled in order to accommodate the acceleration of the target ion species. Mass selection is determined by the velocity and acceleration with which the wave traverses the ion guide, whereby the target species will acquire a higher kinetic energy than all other lighter as well as heaver species. Finite element simulations of this design demonstrate that for small masses a mass resolution M/ΔM ≈ 1000 can be achieved within an electrode stack containing as few as 20 plates. Some of the possible advantages and drawbacks which distinguish this concept from established mass spectrometric technologies are discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Detection of monobromamine, monochloramine and dichloramine using selected ion flow tube mass spectrometry and their relevance as breath markers
Authors: Senthilmohan Senti T. , Kettle Anthony J , McEwan Murray J. , Dummer Jack , Edwards Samuel J. , Wilson Paul F. , Epton Michael J.
Published: February 2008

We report a fast, sensitive, real‐time method to measure monobromamine, monochloramine and dichloramine using selected ion flow tube mass spectrometry (SIFT‐MS). Relative rate coefficients and product distributions are reported for the reagent ions H3O+ and O. Rapid reactions with the haloamines were observed with H3O+ and O but no fast reaction was found with NO+. A slow reaction between NO+ and dichloramine was observed. We demonstrate the feasibility of determining these compounds in a single human breath for which the limit of detection is approaching 10 parts per billion (ppb). We also report preliminary measurements of these compounds in the breath of individuals where the concentrations of bromamine and chloramine ranged from 10 to 150 ppb. Copyright © 2008 John Wiley & Sons, Ltd.
Topology optimization of fluid domains: kinetic theory approach
Authors: Evgrafov A. , Pingen G. , Maute K.
Published: February 2008

We consider the problem of optimal design of flow domains for Navier–Stokes flows in order to minimize a given performance functional. We attack the problem using topology optimization techniques, or control in coefficients, which are widely known in structural optimization of elastic solids and structures for their flexibility, generality, yet ease of use, and integration with existing FEM software. We use a simple kinetic model to approximate the Navier–Stokes system. Arguably, we take a rather unconventional path in the kinetic theory, using it only to gain insight about the Navier–Stokes‐related system of hydrodynamical equations, which we take as our starting point. Thus all the modifications we make to the kinetic models are “hydrodynamically” inspired and we seek no particular physical explanation for them; the only requirement for us is the convergence (at least, formal) of the kinetic equations towards the correct hydrodynamical limit. We formally compute the hydrodynamical limit of the proposed kinetic system, and rigorously establish the existence of flow solutions and their continuous dependence on the design parameters. Optimal controls are shown to belong to a special class (0–1 solutions) for a popular power dissipation minimization problem for viscous fluids.
Long‐term Experience with the Laparoscopic Approach to Perforated Diverticulitis plus Generalized Peritonitis
Authors: Franklin Morris E. , Portillo Guillermo , Treviño Jorge M. , Gonzalez John J. , Glass Jeffrey L.
Published: February 2008

Background

The treatment of perforated diverticulitis is changing form the current standard of laparotomy with resection, Hartmann procedure, and colostomy to a minimally invasive technique. In patients with complicated acute diverticulitis and peritonitis without gross fecal contamination, laparoscopic peritoneal lavage, inspection of the colon, and intraoperative drain placement of the peritoneal cavity appears to alleviate morbidity and improve the outcome. In this article, we report our experience of a laparoscopic peritoneal lavage technique with delayed definitive resection when necessary.

Method and materials

Records of patients who underwent intraoperative peritoneal lavage for purulent diverticulitis at the Texas Endosurgery Institute from April 1991 to September 2006 were retrospectively reviewed.

Results

Forty patients were included in the study, with a male/female ratio of 26:14. The average age was 60 years. Many had associated co‐morbidities. The average operating time was 62 minutes. There were no conversions to an open procedure. Apart from mild postoperative paralytic ileus in six patients and chest infections in two, there were no significant peroperative or postoperative complications. Just over 50% underwent elective interval laparoscopic sigmoid colectomy. During the mean follow‐up of 96 months, none of the other patients required further surgical intervention.

Conclusion

Laparoscopic lavage of the peritoneal cavity and drainage is a safe alternative to the current standard of treatment for the management of perforated diverticulitis with or without gross fecal contamination. It is associated with a decrease in the overall cost of treatment; the use of a colostomy is avoided; patient improvement is immediate; and there is a reduction in mortality and morbidity as definitive laparoscopic resection can be performed in a nonemergent fashion. Perhaps the most important benefit, other than avoiding a colostomy, is the association of fewer wound complications such as dehiscence, wound infection, and the high risk of hernia formation. Laparoscopic lavage and drainage should be considered in all patients in whom medical and/or percutaneous treatment is not feasible. It carries minimal morbidity and should be considered the standard of care.
Biochemical characterization of a chromosomal toxin–antitoxin system in Mycobacterium tuberculosis
Authors: Zhao Longxuan , Zhang Junjie
Published: February 2008

In the present paper, we report the biochemical characterization of a chromosomal toxin–antitoxin (TA) system in Mycobacterium tuberculosis, consisting of the Rv1991c gene and its upstream open reading frame (ORF) termed Rv1991a. Rv1991c was characterized as a toxin with ribonuclease activity and Rv1991a as the antitoxin against Rv1991c. Rv1991a interacted with Rv1991c to form a complex. A promoter located immediately upstream of Rv1991a was identified. Both Rv1991a and the Rv1991a–Rv1991c complex were able to bind to the promoter region of the Rv1991a–Rv1991c operon, indicating that the expression of the Rv1991a–Rv1991c operon can be autoregulated.
Central prostaglandin D2 stimulates food intake via the neuropeptide Y system in mice
Authors: Ohinata Kousaku , Takagi Kuniko , Biyajima Kyoko , Fujiwara Yoko , Fukumoto Shingo , Eguchi Naomi , Urade Yoshihiro , Asakawa Akihiro , Fujimiya Mineko , Inui Akio , Yoshikawa Masaaki
Published: February 2008

We found that prostaglandin (PG) D2, the most abundant PG in the central nervous system, stimulates food intake after intracerebroventricular administration in mice. The orexigenic effect of PGD2 was mimicked by a selective agonist for the DP1 receptor among two receptor subtypes for PGD2, and abolished by its antagonist. Central administration of an antagonist or antisense oligodeoxynucleotide for the DP1 receptor remarkably decreased food intake, body weight and fat mass. Hypothalamic mRNA levels of lipocalin‐type PGD synthase were up‐regulated after fasting. The orexigenic activity of PGD2 was also abolished by an antagonist for neuropeptide Y (NPY) Y1 receptor. Taken together, PGD2 may stimulate food intake through central DP1 receptor coupled to the NPY system.
The 3‐hydroxyacyl‐ACP dehydratase of mitochondrial fatty acid synthesis in Trypanosoma brucei
Authors: Autio Kaija J. , Guler Jennifer L. , Kastaniotis Alexander J. , Englund Paul T. , Hiltunen J. Kalervo
Published: February 2008

The trypanosomatid parasite Trypanosoma brucei synthesizes fatty acids in the mitochondrion using the type II fatty acid synthesis (FAS) machinery. When mitochondrial FAS was characterized in T. brucei, all of the enzymatic components were identified based on their homology to yeast mitochondrial FAS enzymes, except for 3‐hydroxyacyl‐ACP dehydratase. Here we describe the characterization of T. brucei mitochondrial 3‐hydroxyacyl‐ACP dehydratase (TbHTD2), which was identified by its similarity to the human mitochondrial dehydratase. TbHTD2 can rescue the respiratory deficient phenotype of the yeast knock‐out strain and restore the lipoic acid content, is localized in the mitochondrion and exhibits hydratase 2 activity.
Patronage and betrayal in the post-Stalin succession: The case of Kruglov and Serov
Authors: Blauvelt Timothy K.
Published: February 2008

This paper will examine the phenomenon of betrayal in patronage networks in Soviet higher politics by considering one of the most high-profile and significant cases: the betrayal of Lavrenty Beria by two of his top lieutenants, Sergei Kruglov and Ivan Serov, during the post-Stalin succession contest in the spring of 1953.
The Cambridge Companion to August Wilson
Authors: Bigsby Christopher
Published: February 2008

One of America's most powerful and original dramatists, August Wilson offered an alternative history of the twentieth century, as seen from the perspective of black Americans. He celebrated the lives of those seemingly pushed to the margins of national life, but who were simultaneously protagonists of their own drama and evidence of a vital and compelling community. Decade by decade, he told the story of a people with a distinctive history who forged their own future, aware of their roots in another time and place, but doing something more than just survive. Wilson deliberately addressed black America, but in doing so discovered an international audience. Alongside chapters addressing Wilson's life and career, and the wider context of his plays, this 2007 Companion dedicates individual chapters to each play in his ten-play cycle, which are ordered chronologically, demonstrating Wilson's notion of an unfolding history of the twentieth century.